____ 17. Which of the following statements is true about ions?
Cations form when an atom gains electrons.
Cations form when an atom loses electrons.
Anions form when an atom gains protons.
Anions form when an atom loses protons.
____ 18. The metals in Groups 1A, 2A, and 3A ____.
gain electrons when they form ions
all have ions with a 1 charge
all form ions with a negative charge
lose electrons when they form ions
____ 19. Why is the second ionization energy greater than the first ionization energy?
It is more difficult to remove a second electron from an atom because nuclear attraction increases.
The size of atoms increases down a group.
The size of anions decreases across a period.
The nuclear attraction from protons in the nucleus decreases.
____ 20. In which of the following sets are the charges given correctly for all the ions?
Na, Mg, Al
Rb, Ba, P
K, Sr, O
N, O, F
____ 21. What is the element with the highest electronegativity value?
____ 22. What is the energy required to remove an electron from an atom in the gaseous state called?
____ 23. For Group 2A metals, which electron is the most difficult to remove?
All the electrons are equally difficult to remove.
____ 24. Which of the following elements has the smallest first ionization energy?
____ 25. Which of the following statements correctly compares the relative size of an ion to its neutral atom?
The radius of an anion is greater than the radius of its neutral atom.
The radius of an anion is identical to the radius of its neutral atom.
The radius of a cation is greater than the radius of its neutral atom.
The radius of a cation is identical to the radius of its neutral atom.
Essay 26. Atomic size of elements vary in the periodic table.
(Include the following vocabulary = nuclear attraction and nuclear shielding)
A. How does the atomic size change in a period. Explain the causes for change in size within a period.
B. How does the atomic size change in a group. Explain the causes for the change in size within a group.
27. The graphs show the relationship between the electronegativities and first ionization energies for period 2 and period 3 elements.
a. Based on data for these two periods, what is the general trend between these two values?
b. Use nuclear charge and shielding effect to explain this trend.
Chapter 6: The Periodic Table
Answer Section MULTIPLE CHOICE 1. B
ESSAY 26. When an electron is added to an atom, the attraction of the nucleus for any one electron decreases and the size of the ion’s radius increases. When an electron is removed from an atom, there is an increase in the nuclear attraction experienced by the remaining electrons. Consequently, the remaining electrons are drawn closer to the nucleus.
27. a. electronegativitiy increases as first ionization energy increases.
b. both properties depend on the attraction between the nucleus and electrons in the highest occupied energy level. Across a period, the nuclear charge increases, but the shielding effect is constant.