Predicting Formulas of Ionic Compounds Example Problem

Predicting Formulas of Ionic Compounds Example Problem This problem demonstrates how to predict the molecular formulas of ionic compounds. Problem Predict the formulas of the ionic compounds formed by the following elements: lithium and oxygen (Li and O)nickel and sulfur (Ni and S)bismuth and fluorine (Bi and F)magnesium and chlorine (Mg and Cl) Solution First, look at the locations of the elements on the periodic table. Atoms in the same column as each other (group) tend to exhibit similar characteristics, including the number of electrons the elements would need to gain or lose to resemble the nearest noble gas atom. To determine common ionic compounds formed by elements, keep the following in mind: Group I ions (alkali metals) have 1 charges.Group 2 ions (alkaline earth metals) have 2 charges.Group 6 ions (nonmetals) have -2 charges.Group 7 ions (halides) have -1 charges.There is no simple way to predict the charges of the transition metals. Look at a table listing charges (valences) for possible values. For introductory and general chemistry courses, the 1, 2, and 3 charges are most often used. When you write the formula for an ionic compound, remember that the positive ion is always listed first. Write down the information you have for the usual charges of the atoms and balance them to answer the problem. Lithium has a 1 charge and oxygen has a -2 charge, therefore2 Li ions are required to balance 1 O2- ion.Nickel  has a charge of 2 and sulfur has a -2 charge, therefore1 Ni 2 ion is required to balance 1 S2- ion.Bismuth has a 3 charge and Fluorine has a -1 charge, therefore1 Bi3 ion is required to balance 3 F- ions.Magnesium has a 2 charge and chlorine has a -1 charge, therefore1 Mg2 ion is required to balance 2 Cl- ions. Answer Li2ONiSBiF3MgCl2 The charges listed above for atoms within groups are the common charges, but you should be aware that the elements sometimes take on different charges. See the table of the valences of the elements for a list of the charges that the elements have been known to assume.

Topography, an ABA Term to Help Describe Behavior

Topography, an ABA Term to Help Describe Behavior Topography is a term used in applied behavior analysis (ABA) to describe behavior- specifically what behavior looks like. Topography defines behavior in an operational way, free of the coloration of values or expectation. By describing the topography of behavior, you avoid many of the problematic terms that find their way into definitions of behaviors. Disrespect, for example, is more often a reflection of the teachers reaction than the students intent. By contrast, the phrase refusing to comply with a direction would be a topographical description of the same behavior. The Importance of Topography Clearly defining the topography of behavior is especially important for creating appropriate interventions for children whose disabilities are in part defined by behavior, such as emotional and behavioral disabilities and autism spectrum disorders. Teachers and administrators without extensive experience or training in dealing with behavioral disabilities often overreact and create more problems by focusing on the social constructs surrounding misbehavior without observing the actual behavior. When they do so, these educators are focusing on the  function of a behavior  rather than its topography. The function of a behavior describes why the behavior occurs, or the purpose of the behavior; whereas, the topography of the behavior describes its form. Describing the topography of the behavior is much more objective- you are simply stating objectively what happened. The function of the behavior tends to be much more subjective- you are trying to explain why a student exhibited a certain behavior. Topography Versus Function Topography and function represent two very different ways of describing a behavior. For example, if a child throws a tantrum, to explain the topography of the behavior, it would not be enough for a teacher to simply say the child threw a tantrum. A topographical definition might state: The child threw herself on the floor, and kicked and screamed in a high-pitched voice. The child did not make physical contact with other individuals, furniture, or other items in the environment. The functional description, by contrast, would be open to interpretation: Lisa became angry, swung her arms and tried to strike other children and the teacher while screaming in that high-pitched voice she often uses. Each description could be defined as a tantrum, but the former contains only what the observer saw, whereas the latter includes interpretation. It is not possible to know, for example, that a child intended to injure others through a topographical description, but paired with an  antecedent, behavior, consequence (ABC)  observation, you may be able to determine the function of the behavior. It is often helpful to have several professionals observe the same behaviors and then provide both functional and topographical descriptions. By observing the antecedent- what happens immediately before the behavior occurred- and determining the function of the behavior as well as describing its topography, you gain additional insights into the behavior that you are observing. By combining these two methods- decribing the topography of a behavior and determining its function- educators and behavior specialists can help chose a replacement behavior and create an intervention, known as a  behavior intervention plan. Loaded Descriptions Versus Topography To truly understand how topography might describe a behavior, it can be helpful to look at loaded (emotionally tinged) descriptions of a given behavior versus topographical descriptions (objective observations).  Behavioral Learning Solutions  offers this method of comparing the two: Loaded Description Topography Sally got angry and started throwing items during circle time trying to hit others with the items. The student threw items or released items from her hand. Marcus is making progress and, when prompted, can say â€Å"buh† for bubbles. The student can make the vocal sound â€Å"buh† Karen, happy as always, waved goodbye to her teacher. The student waved or moved her hand from side to side. When asked by an assistant to put away the blocks, Joey got mad again and threw the blocks at the assistant trying to hit her. The student threw blocks on the floor. Guidelines for Topography of a Behavior When describing the topography of a behavior: Avoid value-laden descriptions, such as good, best, and bad.Describe as much of the behavior as you can in as objective a manner as possible.Ask another professional to observe the behavior and review the topographical description.Set aside time to observe the behavior more than once.   The topography of a behavior may also be referred to as the operational definition of behavior.