Question

question 47 (1 point)
which of the following statements correctly compares the relative size of an ion to 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.
the radius of an anion is greater than the radius of its neutral atom.

question 48 (1 point)
which of the following factors contributes to the increase in ionization energy from left to right across a period?
an increase in the size of the nucleus
an increase in the shielding effect
fewer electrons in the highest occupied energy level
an increase in the number of protons

question 49 (1 point)
as you move from left to right across the second period of the periodic table
atomic radii increase.
ionization energy increases.
atomic mass decreases.
electronegativity decreases.

Explanation:

• Question 47: Anions are formed by gaining electrons. The added electrons increase electron - electron repulsion, causing the electron cloud to expand. So, the radius of an anion is greater than that of its neutral atom. Cations are formed by losing electrons. The loss of electrons reduces electron - electron repulsion and increases the effective nuclear charge (since there are fewer electrons for the same number of protons), making the cation smaller than the neutral atom.
• Question 48: Ionization energy is the energy required to remove an electron from an atom. As we move from left to right across a period, the number of protons in the nucleus increases. This increases the effective nuclear charge (the net positive charge experienced by the outermost electrons). A higher effective nuclear charge means that the electrons are more strongly attracted to the nucleus, and more energy is required to remove an electron (higher ionization energy). The size of the nucleus does not directly contribute in the way described in option a. The shielding effect (option b) decreases across a period (since electrons are added to the same shell), and the number of electrons in the highest - occupied energy level increases across a period (opposite of option c).
• Question 49: As we move from left to right across a period (e.g., the second period), the atomic radius decreases (due to increased effective nuclear charge pulling electrons closer). Ionization energy increases (as explained in Question 48). Atomic mass generally increases across a period (as we go from lighter to heavier elements). Electronegativity increases across a period (because atoms have a greater tendency to attract electrons as the effective nuclear charge increases).

Answer:

• Question 47: d. The radius of an anion is greater than the radius of its neutral atom.
• Question 48: d. an increase in the number of protons
• Question 49: b. ionization energy increases.