If you’ve been following this blog since its earliest days, you would know that one of the first things we discussed was the scientific method. And if you’ve been a student of the sciences in general, you would know that almost any science class begins with a discussion of the application of the scientific method. Psychology is another one of these subjects that you will likely be introduced to with a thorough explanation of the application of appropriate scientific procedures.
Psychologists are scientists. And as scientists, they do not simply speculate about some of the topics they study. For instance, they would not just simply think of reasons why some people overeat until it hurts or why some people choose to starve themselves. Psychologists, like all other scientists, utilize methods of science. This involves performing experiments and other scientific procedures, in order to gather information systematically and to analyze information that concerns the behavior and mental processes of humans. Only after that can psychologists form conclusions, because they must be based on the results of the procedures they underwent. And then, after all is said and done, using all of these things, psychologists can move on to other questions that they have asked (Bernstein et al. 2012).
On the topic of eating, psychologist Paul Rozin actually set out at one time to see how our decisions to continue eating or stop eating are affected by psychological factors, including the awareness that we have already eaten. It is also known that our decisions to keep eating or stop eating are influence heavily by biological factors, such as signals that are sent from the blood to the brain, that inform your brain of the “fuel” you have left. But, Paul Rozin wanted to know more. He was asking such questions as, “what if you didn't remember that you just ate; would you then keep eating?” (Bernstein et al. 2012).
Rozin actually attempted to perform an experiment based on this question. He performed a series of tests on two men, R. H. and B.R., for the purposes of this text, who suffered from anterograde amnesia, which is a type of brain damage affecting memory, causing the two men to be unable to remember anything for more than a few minutes. The experiment was set up such that the two men had lunch individually with a researcher, where they were served a tray of their favorite food. The men, after eating, were asked to rate their hunger on a scale of 1 to 9, with 1 being “extremely full” to 9 being “extremely hungry.” After this was done, the men would be given water with which to clean their mouths of food residue, and in ten to thirty minutes, the men would be served another tray of food that was identical to the first (Bernstein et al. 2012).
Though many might be compelled to think that biological signals would be enough to keep the two men from eating the second tray of food, this is not the case. These two men, in every session, actually ate all or part of the second meal, and also ate at least part of a third meal in all but one instance. Similar tests were also conducted on J.C. and T. A., a woman and a man who had a different sort of brain damage, not affecting memory. Their results were starkly different from those of the prior two subjects, whose brain damage affected their memories. J. C. and T.A. finished their first servings of lunch but actually rejected the opportunity to eat a second serving of food, in two trials. What this effectively proved is that the memory of when we last ate can actually be a factor in affecting our decisions concerning when we should eat again. And as you might have already been able to predict, these results show more than just that. These results show that eating is more complex than one might think, and is actually controlled by factors ranging from biological ones, to social ones, to cultural ones, to psychological ones, and many more. These findings allow us to conclude that we may eat more often than the times our bodies signal a physical need to eat (Bernstein et al. 2012).
This example of an experiment used by a psychologist to seek a possible explanation to a question is just another way of pointing out the fact that psychologists practice their science like other scientists do, which is by using qualitative and quantitative methods of research following speculations and inquiry, in order to answer questions about behavior and mental processes. Even when a psychologist is not involved in research, he or she benefits from the research of other psychologists and psychologists before him or her. This is because psychologists who do not actively participate in research still apply the results of studies performed by their colleagues in order to do their jobs (Bernstein et al. 2012).
In the previous post, the point of discussion was monatomic ions, particularly predicting the charges on monatomic ions, and naming them, too. This post will add a level of complexity to things, because we’ll discuss polyatomic ions.
As the name suggests, a polyatomic ion is one in which two or more atoms are chemically bonded together, and because they are ionic, carry a net charge. When discussing polyatomic ions, you will often encounter oxyanions, which are anions consisting of oxygen along with another element, that is referred to as the characteristic or central element. Examples of oxyanions are chlorite (ClO2-) and chlorate (ClO3-). From this, you can see that oxyanions tend to have a stem name from the central element, and have a suffix –ite that indicates the lesser number of oxygen atoms in the oxyanion, as well as a suffixe –ate that indicates the greater number of oxygen atoms in the oxyanion. Another example of this is the nitrite ion, NO2-, and the nitrate ion, NO3-. Keep in mind that these suffixes actually don’t indicate how many oxygen atoms are in the oxyanion. The suffixes only tell you the relative number (Ebbing and Gammon 2009).
Sometimes, there are cases in which more than two oxyanions of a substance exist. In such a case, as with oxyanions of chlorine, a couple of which were listed above, a different approach is taken to naming. There are actually four different oxyanions of chlorine, ClO-, ClO2-, ClO3-, and ClO4-. In a case like this, the prefixes hypo— and per—are used, where hypo—would be added to the oxyanion with the least number of oxygen atoms in the case of chlorine, making ClO- hypochlorite ion. For the oxyanion with the second to least number of oxygen atoms in the case of chlorine, ClO4- is known as perchlorate ion. Next, the two oxyanions that have greatest number of oxygen atoms are named using the suffix –ate and the prefix per—. ClO3- is given the name chlorate ion and ClO4- is given the name perchlorate ion (Ebbing and Gammon 2009).
Some polyatomic ions are actually oxyanions with hydrogen atoms attached. Because an H+ ion is provided, these types of oxyanions are often referred to as acid anions. An example of this is monohydrogen phosphate ion, written as HPO42-. This ion is very similar to the phosphate ion, PO43-, with a hydrogen bonded, making the charge less negative. Dihydrogen phosphate is another example, which contains two hydrogen ions, as indicated by the prefix di—, meaning two. Note also that the prefix mono— means one (Ebbing and Gammon 2009).
You will also probably encounter in your study of polyatomic ions, thiosulfate ion, S2O32-. Thio—is a prefix, and it indicates that an oxygen atom in the root ion name has been replaced by a sulfur atom. The root ion is SO42-, so you can see how this works. And if you’ve been paying attention, you will know why the charge on the polyatomic ion does not change (Ebbing and Gammon 2009).
Overall, most polyatomic ions that you will encounter are anions. Cations are much less common as polyatomic ions. Two notable examples are the mercury(I) ion that is also known as the mercurous ion, and the ammonium ion. It is uncommon for a metal ion to be polyatomic, but mercury(I) ion is one case of a polyatomic metal cation, written Hg22+. Remember that the number in the parentheses indicates the charge on a particular atom of an ion. Ammonium is another polyatomic cation that you will become familiar with in your studies of chemistry, and it is composed only of nonmetal atoms, which is another uncommon feature of polyatomic ions. It is written as NH4+ (Ebbing and Gammon 2009).
Though this post was just a brief introduction to polyatomic ions, you should now have an understanding of some important things to know about these ions. For a future post, I am considering creating a diagram with some common monatomic ions as well as polyatomic ions. This would not really be for the purpose of memorization, but for reference. Also, look forward to some upcoming MCAT questions. We are closing in on chapter two of general chemistry and that is why I have been focusing heavily on it as opposed to other subjects. Mentally, I am preparing myself to soon do a much-needed chapter review. Good luck and happy studying! I hope to have you around for the next post.
Hi, guys. As you can see, the site has undergone a bit of an overhaul recently, as I have simplified the design and made the text a bit easier on the eyes. The site may continue to be updated and changed over the next few weeks or so, as I finalize a plan for what I would like the site to look like. Originally, when I considered making this site, I was more concerned about the content that I would be placing on it, than the aesthetics associated with it. In the future, I may even potentially create a store from which fans and readers can shop. On another note, you may or may not have noticed that my posts are not showing subscripts and superscripts. At this point, it is not something I can fix, and has to do with the website host’s text editor. Please bear with me on this, and for now, understand that when I write formulas, directly following the element’s abbreviation is the subscript or superscript associated with it.
Moving on, in this post I will begin a discussed on how to name simple compounds. This post may be broken down into a few separate posts, because there is a lot to cover. We will utilize the appropriate rules of chemical nomenclature as defined by IUPAC, or the systematic naming of chemical compounds. As you can imagine, with the millions of compounds that have come to be known in our current day and age, without a system that defines a set of rules for naming compounds, coping with the multitude of substances that exist would be extremely difficult, on top of being disorganized. Back in the day, compounds might have been named after people, places, or the characteristics they had, such as Glauber’s salt for its discoverer, J. R. Glauber, which is actually sodium sulfate. This is no longer the case (Ebbing and Gammon 2009).
We learned what organic compounds were, but a small note on inorganic compounds is that they are composed of elements other than carbon. Remember, however, that there are exceptions to the rule, and many carbon-containing compounds are indeed inorganic compounds, such as carbon monoxide, carbon dioxide, and cyanides, for whatever reason. Because naming can get complex, this post will focus on the naming of inorganic compounds, specifically beginning with simple, ionic compounds that are monatomic (Ebbing and Gammon 2009).
Ionic compounds, as we learned before, are compounds containing ions. Metal and nonmetal atoms are usually a part of ionic compounds, such as in the case of NaCl. Moreover, exceptions to this also excise, as in the case of ammonium salts such as NH4Cl. The way in which you name an ionic compound is by first giving the name of the cation, followed by the name of the anion. For example, if you’re given the name of a substance that is potassium sulfate, you know that potassium is the cation, and sulfate is the anion (Ebbing and Gammon 2009).
When naming a monatomic ion, which is an ion that is composed of a single atom, you must know the charge of the ion. There are some rules to know for predicting the charges of ions, and then rules for naming the monatomic ions. I would like you to have a periodic table of elements with you as you go over these rules and regularities. It will help you to visualize the information properly.
Predicting Charges on Monoatomic Ions: Rules as Per Ebbing and Gammon
Naming Monoatomic Ions: Rules as Per Ebbing and Gammon
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