Causes of Attention-Deficit Hyperactivity Disorder

Causes of Attention-Deficit Hyperactivity Disorder ADHD Print The Causes of Attention-Deficit Hyperactivity Disorder By Keath Low Keath Low, MA, is a therapist and clinical scientist with the Carolina Institute for Developmental Disabilities at the University of North Carolina. She specializes in treatment of ADD/ADHD. Learn about our editorial policy Keath Low Medically reviewed by Medically reviewed by Steven Gans, MD on June 16, 2019 Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital. Learn about our Medical Review Board Steven Gans, MD Updated on August 02, 2019 ADHD Overview Symptoms Causes Diagnosis Treatment Living With In Children In This Article Table of Contents Expand Genetics Toxins Exposure to Substances in Utero Illnesses  and Injuries What Does Not Cause ADHD View All The exact cause of ADHD isnt known. But, researchers suspect there may be several factors that play a role in determining whether someone might develop ADHD. Verywell / Brianna Gilmartin Genetics Whether you have recently been  diagnosed with ADHD  or have been living with ADHD for many years, a question almost all adults ask is:  Will my children have ADHD,  too? The answer is:  It depends. ADHD is primarily a hereditary disorder. It is estimated that the percentage of genetic contribution to ADHD is over 70%.?? Despite this strong genetic link, having ADHD doesn’t automatically mean youll pass it on to your child. This is because it is a combination of genes and environmental factors that determine whether a child develops ADHD. Children can inherit ADHD genes without them being activated. For example, one research study found that one-third of fathers with ADHD had children that also developed ADHD.?? If you inherit ADHD from a parent, their ADHD presentation (or subtype) whether Inattentive, Hyperactive-Impulsive  or combined,  will not influence the ADHD presentation you have. To date, several gene candidates have been found in families who demonstrate ADHD; however, scientists feel that it is not one particular gene but the interaction of several of these genes and the environment that cause ADHD symptoms to manifest.?? ADHD is not a sex-linked condition. In other words, ADHD does not occur only in males and is thus not passed down only from a father to the children. So often people think, “It’s only fathers who can have ADHD, and if the dad doesn’t have ADHD then the child can’t possibly have it.” This is inaccurate.?? Although ADHD is more frequent in males than females, it is important to understand that both mothers and fathers can have ADHD. Toxins Exposure to lead (even low levels) can result in hyperactivity and inattention. Lead can be found a variety of places, such as in the paint of homes built before 1978 or previously in gasoline.?? Exposure to Substances in Utero A mothers health and habits during pregnancy can also play a role in the development of ADHD. Poor nutrition and infections during pregnancy can increase the risk of ADHD, for example. Theres also evidence that says using substances during pregnancy increases the risk that the child will develop ADHD. Heres what the research says: Smoking  A 2018 study published in Pediatrics found a significant relationship between smoking during pregnancy and the likelihood of a child having ADHD. The risk of ADHD was greater in children whose mothers were heavy smokers. The study couldnt conclude that smoking causes ADHD but it did indicate that a correlation exists.Maternal Alcohol Use - Some studies have found that mothers who drink during pregnancy are more likely to have children with ADHD. A 2018 study found that the use of at least four drinks or the regular use of low-moderate alcohol doses during pregnancy was associated with significantly increased odds of subsequent child ADHD. A 2017 study, however, found that there was no link between maternal alcohol use and a clinical ADHD diagnosis in children. This study suggested that children may develop some symptoms of ADHD if their mother used alcohol, but they didnt necessarily qualify for an ADHD diagnosis. 10 Risks of Smoking During Pregnancy Certain Illnesses  and Injuries Illnesses such as meningitis or encephalitis can result in learning and attention problems.????? A small percentage of the population will manifest ADHD symptoms as a result of brain damage, such as an early brain injury, trauma or another impediment to normal brain development.?? What Does Not Cause ADHD As more research is carried out, not only are we learning what causes ADHDâ€"we are also learning what does not cause ADHD.  Although the following things have sometimes been thought to contribute, research is clear that these things do not lead to ADHD: Watching  TV  Diet, including too much sugarHormone disorders (such as low thyroid)Poor parentingPlaying video and computer games A Word From Verywell Its likely that ADHD stems from a variety of symptoms. Someone who has a genetic predisposition, for example, may encounter environmental factors that also contribute to the development of ADHD.?? How Is ADHD Diagnosed?

William Shakespeare Was Quite Shakexperienced At Creating

William Shakespeare was quite Shakexperienced at creating english words that would last from 1600 all the way to 2017. In fact, he invented more that 1,700 words that many people use on a regular basis. Without some of the words that Shakespeare invented, life would kinda suck. Every day would be a struggle. You know when there is a word, and all of the synonyms come to mind, but never the word that you want? Deep down, you know the synonyms will suffice but those words aren t...The word. It bothers you for the rest of the day, until†¦ all of the sudden it pops into your brain. And just like that the burden of not knowing the word has disappeared. Without Shakespeare, that burden would never go away, because the word you are looking for†¦show more content†¦But there was one small problem: Scotland already had a King, and a good one at that. His name was Duncan. Macbeth started to think about killing him, but then decides he can’t, because he is being so kind to him and his family. Lady Macbeth does not help the situation by saying â€Å"When you durst do it, then you are a man† (Shakespeare 1.7.49) She is basically calling Macbeth a coward until he kills him. Macbeth’s wife, his ambition and crave for power caused him succumb to the horrific thought of killing Duncan for the sole reason that he wanted to be king. Macbeth even admitted, â€Å"I have no spur. To prick the sides of my intent, but only. Vaulting ambition, which o erleaps itself, And falls on th other†¦ â€Å"(Shakespeare 1.7.25-28). He is saying had he had no reason to kill Duncan, only his ambition was influencing and convincing his mind that it was okay. It is a toss up on whether Macbeth is really a tragic hero, or if he is just a monster. Technically a tragic hero is defined as a protagonist who makes a error in judgement, that leads to their destruction. Macbeth made an error by listening to his wife, (lol) who convinced him to kill Duncan, which ul timately led to both of their deaths. As the wise Derek Zoolander once said â€Å"You mean, if you pull the thread the whole thing will unravel?† Yes, and that is exactly what happened to Macbeth. He expected that killing Duncan, Banquo, and Macduff’s family would be a one time thing, and he would

All About Argumentative Essay Writing Work Samples

All About Argumentative Essay Writing Work Samples Understanding Argumentative Essay Writing Work Samples An argumentative essay requires you to choose a topic and have a position on it. You need to have the strong personal opinion on this issue you intend to discuss in your argumentative essay. Picking an argumentative topic isn't that easy. The Topic When it regards an argumentative essay, the very first thing that you should decide on is the topic. Characteristics of Argumentative Essay Writing Work Samples To finish a great paper, argumentative essay structure also needs to be considered. By now you're probably keen to find a great argumentative essay outline template. When you develop this kind of essay, you should make your claims by your composition so it will be open fordebate. With an incorrect thesis statement, the essay writing efforts aren't going to yield great fruits. Moreover, our English-speaking writers make sure every order has original content and an app ropriate structure. So as to write a great paper, an individual must be a specialist not only in a specific subject but in writing as well. When you purchase an argumentative essay from Ultius, you may rest assured our expert writers will do anything it requires to be sure that the sample order is 100% correct before you login and download this, and if your criteria has changed, no issue, absolutely free revisions are included with each order. The thing you ought to do to be able to structure an argumentative essay is to set a claim that's debatable. The Fundamentals of Argumentative Essay Writing Work Samples You Can Benefit From Starting Right Away Each paragraph needs to be restricted to the discussion of one general idea. A five-paragraph essay might be as long as 2000 words and you have to keep an eye about the quantity of words in 1 page. The thesis statement that comes almost to the conclusion of the final paragraph stipulates the standpoint of the author on the subjec t. If you've got more information to share, you might include as many as five body paragraphs. When it has to do with writing an argumentative essay, the most essential issue to do is to select a topic and an argument you can really get behind. Pick something you are obsessed with. The first thing you're likely to have to do is to choose a topic that has more than one clear side. Without an excellent evidence, nobody is likely to believe my words. A Secret Weapon for Argumentative Essay Writing Work Samples Your essay should consist of recent statistics and data from reliable sources. You devote a whole lot of education on writing argumentative essays. Argumentative essay topics are so important since they are debatableand it's critical to at all times be critically considering the world around us. Frequently students are permitted to choose argumentative essay topics by themselves, which can be both challenging and interesting at the identical moment. If You Read Nothing Else Today, Read This Report on Argumentative Essay Writing Work Samples Argumentative essays utilize logic, facts, and reasoning to find out the victor. Regardless of the amount or type of research involved, they must establish a clear thesis and follow sound reasoning. An argumentative essay is a kind of thesis or composition in which you have to present your view and endeavor to convince others your facts and arguments are correct. Besides, don't forget that the secret to a prosperous argumentative essay is in finding suitable evidence to strengthen your opinion. The chief reason why somebody is writing an argumentative essay is to make an effort to persuade or sway another individual or perhaps a group of men and women in your rightness in a particular theme. You might also want to incorporate a quick discussion of more research that needs to be completed in light of your work. Besides general knowledge you have concerning this issue, you won't mind dedicating some oppo rtunity to research, writing procedure, and other aspects essential for the high-quality essay. At precisely the same time, it also needs to be simple to research, that way you'll discover evidence to support claims you make. So when you purchase sample argumentative essays from Ultius, you will have the peace of mind you have earned from a comprehensive writing service. An argumentative essay example will reveal the should possess some critical components which make it better in the practice of convincing. You will be given a perfectly crafted paper that fulfills your requirements and can help you improve your academic outcomes! For instance, in college, you might be requested to compose a paper from the opposing perspective. What Is So Fascinating About Argumentative Essay Writing Work Samples? Only then the essay would wind up being good. It needs to have a bit of structure, unlike a regular essay. An argumentative essay is a certain sort of academic writing. It may b e confused at times with expository writing due to their similarities. Writing has existed for quite a very long moment. Essay writing per se is no simple job to do. Writing an argumentative essay can at times be confusing since you don't necessarily understand how to compose a convincing argument. Writing a persuasive, argumentative essay can be challenging, and at times it can find a little confusing. Argumentative Essay Writing Work Samples Fundamentals Explained Lots of people find writing as an effective method to share their suggestions and opinions. It's completely understandable to look for help whenever you don't have sufficient time or skills. All works are finished from the scratch utilizing personal and one of a kind strategy. Even though both work to the improvement of a business, the broad disparity has the capability to induce a good deal of grudge and bad vibes. The Downside Risk of Argumentative Essay Writing Work Samples Argumentative essay ought to be convincing for you to attain superior grades. An argumentative essay is among the many academic essay types. It is one of the most difficult papers you can create. Every argumentative essay ought to depend on a topic that may be debated.

Business Plan Coffee Shop Free Essays

Coffee Shop for $ 50-100 thousand MARKET SITUATION Coffee boom that seized America, and then Portugal, has come to us. Is explained by the fact that the growing popularity of refreshing drink in the population, attracts more and more attention to this business. Existing Place of public may be divided into three categories: -Coffee house, so to speak, in its purest form, where the visitor suggest several varieties of coffee. We will write a custom essay sample on Business Plan Coffee Shop or any similar topic only for you Order Now – Coffee house with the addition of the â€Å"kitchen†, which attracts customers not only the coffee menu but also the possibility of a tasty and inexpensive meal. Most of the customers in set meals (lunches) and breakfast. – Coffee Shop – a bookstore, a favorite place of party intellectuals:writers, journalists and inveterate book lovers. Over coffee here it is possible read your favorite book or learn the news of the book market. Should be distinguished from the usual coffee cafe. First, Coffee Shop offers enhanced assortment number coffee and coffee prepared on the basis of drinks. Second, this place is more democratically and offers a pleasant leisurely conversation. Therefore the future owners of such establishments need to be prepared for the fact that customers will stay long here longer than in a normal cafe. Idea, concept First, you need to pay attention to the development of of the concept the institution. This is the cornerstonewhich in many respects determines the success of coffee. In the interior fast-service places emphasis on of coffee as the primary attribute. Place your bets on impeccable service, delicious cuisine original design dishes offered, unusual interior decoration disciplined waiters and special mood. Visitors have to want to return to the coffeehouse and on. It will be a classic style. How much it costs According to experts, in order to open kofeynyuna 20-30 seats in business need to invest at least $ 50 thousand. Payback period of coffee – 1,5-3 years. Licensing documentation Package permits to open a coffee shop and a cafe or restaurant is no different. Need a patent for trading activities, the certificate of registration. On the â€Å"documentary† aspect of the matter will go 3-6 months. Is assumed to replan and renovation of premises. It is necessary make the reconstruction project. It is also necessary have the consent of Division for the improvement, sanitary station and firefighters. ADVERTISEMENT For promotion of coffee would need about a year in which to be active advertising support. Important area adjacent to the institution. Coffee Shop – setting more local value if it does not differ exclusive assortment. LOCATION To estimate the location of the future coffee use the the following criteria. Stream of customers. No one will argue that the center is of the city – the most profitable place for such institutions. A huge number of people who work there, just walking, can provide a comfortable existence no one coffee shop. Characteristics of the competition. Question should be askedand which facilities are close to the coffee shop of the future? If it intersects the assortment and pricing policies with the majority of potential neighbors, it is better to think about a different area. { Because recapture clients from working and already gained popularity competitors always extremely difficult. } How to cite Business Plan Coffee Shop, Essay examples

Normal & Abnormal Individuals Essays - , Term Papers

Normal & Abnormal Individuals During the course of the last fifty years, society has changed significantly. In modern society a great emphasis is placed on individualism and diversity within a society. It is rare that an individual would be ridiculed or forced to change simply for not complying with what society views as normal. This has not always been the case though. The nineteen fifties were much different. This was an era of social conformity. The members of society who were intent on maintaining this social state ostracized individuals who were considered abnormal. Such abnormal individuals just simply accepted the fact that they were not part of this normal society. Because of society's influence, these people sought help in psychiatric wards in attempts to better themselves and thus fit into society. By doing so, they let society conform and mold them into what was thought as normal. Ken Kesey was a man in this era that did not believe in social conformity. Kesey, along with his followers set off on a mis sion to open the minds of people who were focused on maintaining this status quo. Ken Kesey's journey led him to write One Flew Over The Cuckoo's Nest. This novel focuses on the struggle between individuals who are intent on keeping things the same with those who are considered different. Harding is a character in the novel that is limited by opposing forces of society and who in turn, seeks refuge in hopes to be accepted. With the influence of McMurphy, Harding changes from an apprehensive rabbit to a self-assured man. This change illustrates Kesey's view that an individual can realize the worth of their life through self-acceptance and reliance on ones self rather than conforming to social norms. Harding admits himself in the psychiatric hospital because he is abnormal in a society that highly values normality. [He] discovered at an early age that [he] was?different? ?[He] indulged in certain practices that?society regards as shameful(pg. 294). Admitting himself in the hospital is Harding's way of succumbing to the forces of society. He simply accepts the fact that without help he will never fit in the real world. Harding knows that This world belongs to the strong?(pg.62). For this reason he felt that is why he belonged in the hospital. The hospital is a place where [a] good strong wolf like the Nurse [could] teach [them their] place(pg.62). Initially with no self-esteem, Harding lets the Nurse and the other hospital staff tell him how to live. When initially questioned of his abnormal life by the other patients and the staff, Harding [had] his thin shoulders folded nearly together around himself?his hands trapped between his knees?trying to look calm-but he's chewing his ch eeks?not calm at all (pg.54). Harding is a nervous man who finds it difficult to deal with his differences and simply follows society's commands in order to keep things easy. Harding's views and behaviors start to change slowly as he associates more with Randle McMurphy. McMurphy enters the ward involuntarily and has a much different outlook on life than the other patients. McMurphy places a great influence on being an individual and goes to great extents to be just that. He is a leader and not a follower. His straightforward tactics and self-confidence allow him to freely express his values. Along with these attributes, McMurphy also treats the other patients normal and does not treat them how society does. By treating them as equals and by instilling into them his views and ethics, they are able to see the world differently. McMurphy's concern with the music that dulls the senses shows another side of him as well. It shows his concern and consideration for his peers. A more important feature of McMurphy is that he shows no shame. This shows the patients, including Harding, that there is no need to fell shame for being who they are. Amongst these things, McMurphy teaches the patients the power of trying and believing in ones self. McMurphy attempts to lift the panel in order to try to escape and he fails. Even though he failed in the end, he still had enough confidence to try. The lesson is learnt that it is far better to try

To find the best position of a lens to give the best magnification Essays

To find the best position of a lens to give the best magnification Essays To find the best position of a lens to give the best magnification Essay To find the best position of a lens to give the best magnification Essay Aim To find the best position of a lens to give the best magnification. Theory There are two basic types of lenses, convex lenses and concave lenses. A convex lens is also called a converging lens and a concave lenis is also called a diverging lens. Convex lenses are thicker in the middle than at the edges and concave are thinner in the middle than at the edges, which is exactly the opposite. The diagram below shows some examples of both types of lenses. Diagram 1 If a beam of light is directed parallel at a convex lens then the light is brought to focus by the lens. If the beam of light is directed along the lens axis (the line through the centre of each surface), the rays are brought to a focus on the axis at the focal point of the lens. The focal length (f) of a convex lens is the distance from the lens to the point where the rays are brought to a focus. Diagram 2 If a beam of light is directed parallel at a concave lens then the light rays are made to diverge from the lens. The focal length (f) of a concave lens is the distance from the lens to the point where the rays appear to diverge from. Diagram 3 Ray diagrams are used for showing how images are formed and predicting where the image will be formed. For simplicity, rays are shown bending at the line through the middle of the lens. In reality, bending takes place at each surface. Examples are shown below. Lenses are made up of a large number of small-angle prisms. Keep all the previous information in mind, at distance h from the optical centre P of a lens, (see diagram below). If a paraxial ray (a ray that is close to the axis that is making small angles with it) parallel to the axis changes angle when heating the lens there is always going to be a small deviation (D) after. Since the lens is small angled and is refracted trough the principal focus then the tangent of a small angle equals the small angle in radians, D=h FP Diagram 4 Now look at the diagram on the next page. If a paraxial ray from O is incident on the lens at distance h from the axis, it must also suffer deviation (D). Since all rays suffer the same amount of deviation. In the triangle IOM, the exterior angle of a triangle equals the sum of the interior opposite angles. Converging Diverging D=?+? D=?-? D=h h D=h h OP IP IP OP Therefore FP OP IP FP IP OP The above formula explains how we get; 1 1 1 where u=object distance v u f f=image distance v=focal length Diagram 5 Magnification is defined as: magnification (m) = image height object height and image height image distance object height object distance magnification = v u=object distance from lens. u v=image distance from lens Prediction From all my preliminary work, which was done on an applet at school, I predict that as the object moves towards the lens, the image becomes farther away (from the lens) therefore the magnification will increase. Variables In my experiment there are three key variables, which are: Object distance, which is the independent variable. Control variables are the variables that are changed. I will change the object distance of the lens. Image distance, which is the dependent variable. The dependent variable is the data collected, so in this experiment it will be the image distance. Focal length, which is the control variable. Control variables are the factors, which help to keep the experiment a fair test. In this experiment the control variable is the focal length. Safety Precautions To protect myself from any danger a few tasks have to be done. * Be careful with the power pack the ray box is connected with. * Do not hold the light bulb since it gets very hot. * Do not shine the light in your eyes or anyone elses. * Do not break your lens. Fair Test To make sure the experiment is fair a few factors have to be taken into consideration. To make it a fair test then I will use the same ray box, same metre ruler, same slide, same lens and the same screen. To make the experiment accurate and to prevent anomalies I will repeat the whole experiment at least three times and take an average reading. Equipment Lens Screen Ray box Slide Metre Ruler Method 1. Set up the diagram as shown below. 2. Move the object closer to the lens and measure the image distance as well as the object distance. 3. Calculate the magnification. 4. Repeat step 2 several times and repeat the experiment three more times and take an average reading. Diagram Preliminary work My preliminary work was done using a java applet that can be found on the following website:http://members.nbci.com/-XMCM/surendranath/Applet.html. My results are shown below. OBJECT DISTANCE (mm) IMAGE DISTANCE (mm) MAGNIFICATION (mm) 200 200 1 180 225 1.25 160 266.7 1.7 140 350 2.5 120 600 5 100 10100 101 80 -400 -5 60 -150 -2.5 Actual Experiment results. OBJECT DISTANCE (Cm) IMAGE DISTANCE (Cm) MAGNIFICATION (Cm) 10 Infinity (INF) Infinity (INF) 15 Infinity (INF) Infinity (INF) 16 200 12.5 18 118 6.5 20 65 3.25 22 53 2.409 24 41 1.7083 25 40 1.6 26 37 1.42 28 33 1.179 30 30 1 45 22 0.48 45 22.5 0.5 Measurements have been converted to metres. U 1/u (1/u) 2 V 1/v (1/v) 2 1/u?1/v 0.16 6.25 39.063 2 0.5 0.25 3.125 0.18 5.5556 30.864 1.18 0.8475 0.7182 4.7081 0.2 5 25 0.65 1.5385 2.3669 7.6923 0.22 4.5455 20.661 0.53 1.8868 3.56 8.5763 0.24 4.1667 17.361 0.41 2.439 5.9488 10.163 0.25 4 16 0.4 2.5 6.25 10 0.26 3.8462 14.793 0.37 2.7027 7.3046 10.395 0.28 3.5714 12.755 0.33 3.0303 9.1827 10.823 0.3 3.3333 11.111 0.3 3.3333 11.111 11.111 0.45 2.2222 4.9383 0.22 4.5455 20.661 10.101 42.491 192.55 23.324 67.353 86.694 U is the object distance independent variable. V is the image distance dependent variable. Plot (1/u) along the x-axis. Plot (1/v) along the y-axis. Graph See graph paper. Ex = E 1/u = 42.491 Ey = E 1/v = 23.324 Ex2 = E (1/u) 2 = 192.55 Ey2 = E (1/v) 2 = 67.353 Exy = E (1/u?1/v) = 86.694 x =Ex/n =42.491/10 =4.2491 y = Ey/n = 23.324/10 = 2.3324 Sxx =Ex2 nx2 =192.55-10?4.24912 =12.0015 Syy = Ey2 ny2 =67.353-10?2.33242 =12.9510 Sxy = Exy-nxy =86.694-10?4.2491?2.3324 =-12.4120 Least Squares Fitting Gradient = ? =Sxy/Sxx =-12.4120/12.0015 =-1.0342 Formula for line of best fit. (y-y) = ?(x-x) y=?x+y-?x Intercept =y-?x =2.3324-(-1.0342?4.2491) =6.7268 Therefore, y=-1.0342x + 6.7268 Since y=1/v x=1/u 1/v= -1. 0342/u + 6.7268 1/f = 6.7248 f = 0.14865m Analysis The first two points are left out, as it was impossible to accurately locate the image. I will do a least squares analysis on the remaining points. The object distance against magnification graph forms a curve. This curve represents exactly what I had predicted that the nearer the object is to the lens the better the magnification. The graph that shows the relationship between 1/u and 1/v shows a negative correlation of points and this means that as the object distance decreases the image distance increases. I had one difficulty when doing the experiment and that was the judgment in measuring the distance from the lens to the image (1 cm error) and from the object to the lens (0.5 cm error). Theoretically the best magnification should be when the object distance is nearest to the lens but before the focal point. This is represented in the experimental results above. Evaluation I think my plan worked out because I got the results I expected to get. My results for my experiment are quite accurate and reliable but there is a marginal error. My experiment could be improved if I used a tape measure instead of a ruler because there was a marginal error in measuring the object distance and image distance. The first two points were anomalous. I think that if I did the experiment again I could change the focal length.

Definition of a Chemical Period - Chemistry Glossary

Definition of a Chemical Period - Chemistry Glossary In chemistry, the term period refers to a horizontal row of the periodic table. Elements in the same period all have the same highest unexcited electron energy level or same ground state energy level. In other words, each atom has the same number of electron shells. As you more down the periodic table, there are more elements per element period because the number of electrons allowed per energy sublevel increases. The seven periods of the periodic table contain naturally-occurring elements. All elements in period 7 are radioactive. Period 8 consists solely of yet-to-be-discovered synthetic elements. Period 8 is not found on the typical periodic table, but does show up on extended periodic tables. Significance of Periods on Periodic Table Element groups and periods organize the elements of the periodic table according to periodic law. This structure categorizes elements according to their similar chemical and physical properties. As you move across a period, an atom of each element gains an electron and displays less metallic character than the element before it. So, elements within a period on the left side of the table are highly reactive and metallic, while elements on the right side are highly reactive and nonmetallic until you reach the final group. The halogens are nonmetallic and not reactive. The s-block and p-block elements within the same period tend to have different properties. However, d-block elements within a period are more similar to each other.