Study Island Copyright © 2015 Edmentum - All rights reserved. Generation Date: 03/16/2015 Generated By: Kristina Brown 1. Which family of elements contains a full outer shell of electrons? A. halogens B. transition metals C. noble gases D. lanthanides 2. Most main group elements found within the same family on the periodic table tend to have A. the same atomic radius. B. the same chemical activity. C. the same number of valence electrons. D. the same electron affinity. 3. Which of the following statements is true of pure substances? A. Pure substances have definite properties. B. Pure substances are composed of only one kind of material. C. Elements and compounds are examples of pure substances. D. all of these 4. As you move down a middle column of the periodic table, what periodic trend would be expected? A. a decrease in reactivity B. an increase in electron affinity C. a decrease in ionization energy D. an increase in non-reactive atoms 5. Students studying different elements know that one particular element has the following set of properties: It has a low melting point. It has a low boiling point It exists as a diatomic molecule in the gas phase. It has seven valence electrons. It readily reacts with metals to produce a salt. Which of the following is most likely the element whose properties are listed above? A. potassium B. krypton C. bromine D. strontium 6. The atomic number of an element is equal to the number of protons that the element contains. What is the atomic number of the element boron? A. 10.81 B. 5 C. +3 D. VA 7. ________________ cannot be broken down further by physical or chemical means and is therefore considered _________________. A. Iron, an element B. Marble, a mineral C. Lead, a compound D. Steel, a mixture 8. The periodic table consists of elements following a repeating pattern of A. outermost electrons. B. excess neutrons. C. hydrogen ions. D. nuclei. 9. Technology Enhanced Questions are not available in Word format. 10. Which of the following compounds contains a transition metal? A. iron oxide (FeO) B. magnesium bromide (MgBr2) C. sodium chloride (NaCl) D. potassium hydride (KH) Answers 1. C 2. C 3. D 4. C 5. C 6. B 7. A 8. A 9. -- 10. A Explanations 1. The elements in group 18 of the periodic table are noble gases. They all have a full outer shell of electrons. This property makes all these elements very stable and unreactive. 2. The columns of the periodic table are grouped by common properties into groups, or families. One common property is that main group elements (i.e., non-transition metals) in the same family tend to have the same number of valence electrons. A notable exception to this trend is helium which only has two valence electrons, while other elements within the same family have eight. 3. Pure substances are composed of only one type of material, and they have definite properties. Elements are the simplest pure substance, since they are composed of only one type of atom. For example, the element carbon is a pure substance, because it is only composed of carbon atoms. Compounds are also pure substances because they are composed of only one type of molecule. For example, water is a pure substance that is composed of two atoms of hydrogen chemically combined with one atom of oxygen. Once combined, water molecules are classified as pure substances because they cannot be broken down by ordinary means. Therefore, the correct answer is all of these. 4. Metals make up the majority of the periodic table and are found on the middle to left side of the periodic table. If you are traveling down a column consisting of metals, the reactivity and atomic radius increases as the ionization energy and electron affinity decreases. 5. Halogens, or "salt-formers," are located in group 17 of the periodic table. The halogens have the following properties: They have low melting points and low boiling points. They exist as diatomic molecules in the gas phase. They have seven electrons in their outermost shell, which means they have seven valence electrons. They are highly reactive nonmetals. They tend to gain electrons and form negative ions. Fluorine, chlorine, bromine, and iodine are the most common of the halogens. Astatine is a halogen also. However, it is a radioactive element with an extremely short half life, so it is rarely found in nature. 6. Elements on the periodic table are organized in order of their atomic numbers. Since the atomic number is equal to the number of protons, this number is always a whole number. According to the periodic table, the atomic number of the element boron is 5. 7. An element is a substance that contains only one type of atom and cannot be broken down by chemical or physical means. 8. The periodic table consists of elements following a repeating pattern of outermost electrons, or valence electrons. Valence electrons determine the chemical properties of atoms. The following table shows the valence electrons for the groups with representative elements. Group (column) Valence Electrons 1 1 2 2 13 3 14 4 15 5 16 6 17 7 18 8 Helium is an exception to the above pattern. Its atoms only have 2 valence electrons, instead of 8. The number of valence electrons varies for the transition elements (groups 3-12), so their patterns are less predictable. 9. -- 10. Transition metals are those that usually have incompletely filled d orbitals. Since the electron configuration of iron is 1s22s22p63s23p64s23d6, iron is a transition metal. All of the other elements listed are representative elements. .