Chemistry Test 2 Study Guide Answer Key
1. An atom that has a positive or negative charge is called: an ion
2. If an atom gains an electron, the overall electrical charge of the atom becomes:
negative
3. A Lewis Dot Structure (electron dot diagram) illustrates an atom’s valance
electrons
4. The element Aluminum is on the periodic table. Draw the Lewis dot structure for
aluminum:
Al
5. The electron configuration for gallium is 1s22s22p63s23p63d104s2 4p1 or
[Ar]3d104s24p1
6. A positively charged ion is created when an atom loses 1 or more electrons
7. Calculate the total number of atoms in the following compound NaCl – 2 atoms
(1 Na and 1 Cl)
8. In an atom, protons have a positive electrical charge and electrons have a
negative electrical charge.
9. Families or groups on the periodic table share similar chemical properties
because, each element has the same number of electrons.
10. How many sodium ions do you predict there would be in the ionic compound
sodium phosphate? 3 atoms
11. How does an ion with a charge of 2+ form? By losing 2 electrons
12. How many electrons does a sulfur atom gain when it becomes a sulfide ion? 2
atoms
13. For an ionic compound, the name of the positive ion comes first, followed by the
name of the negative ion.
14. The formula for sodium bromide is as follows: NaBr
15. The element Hydrogen is in group 1 on the periodic table. Draw the Lewis dot
structure for this element. H●
16. During a chemical or physical change, matter cannot be created or destroyed.
Which law accurately describes this concept? The law of Conservation of Mass
17. When describing valence electrons, you are describing the electrons that are in
the highest energy level of an atom.
18. When the pressure of a gas is increased, the volume of the gas decreases. Which
law does this describe? Boyle’s law
19. Most of the fuels that are burned to yield energy contain carbon. Coal is mostly
the element Carbon
20. Which gas makes up 80% of the atmosphere? Nitrogen
21. An atom of Fluorine has 10 neutrons. What is the total number of other
subatomic particles in this atom? 9 protons and 9 electrons
22. How many electrons can an orbital hold? A number of electrons that depends on
the energy level.
23. Unstable atomic nuclei that release fast-moving particles and energy are called
isotopes
24. A covalent bond in which electrons are shared unequally is a Polar Bond
25. How many electrons are shared in a single covalent bond? 1 electron
26. In the following answers, the first number represents the mass number of an
atom; the second number represents the atomic number of the same atom.
Which atom will have the greatest number of electrons? 56, 25
27. What does Dalton’s theory state? All matter is made of atoms.
28. What does Rutherford’s theory state? The atom consisted of subatomic particles
called protons and electrons.
29. Which subatomic particles are most directly involved in chemical bonding?
Valance electrons.
30. The figure below shows a periodic table with the position of one element
indicated by an X. How would this element (X) be classified? Non-metal