Question

Rank the ions in each set in order of decreasing size, and explain your ranking:

Answer 1

Answer:

a) Se²⁻> S²⁻ > O²

b) Te²⁻ > I- >Cs+

c)  Cs+ > Ba²⁺ > Sr²⁺

Explanation:

(a) Se²⁻, S²⁻, O²⁻

In general, ionic radius decreases with increasing positive charge.

As the charge on the ion becomes more positive, there are fewer electrons.

The ion has a smaller radius. In general, ionic radius increases with increasing negative charge.

For ions of the same charge (e.g. in the same group) the size increases as we go down a group in the periodic table

Se²⁻> S²⁻ > O²

(b) Te²⁻, Cs⁺, I⁻

Te²⁻ > I- >Cs+

Te2- hast the biggest size, because of the double negative charge.

Cs+ has the smallest size since it has the most positive charge, compared to Te2- and I-.

(c) Sr²⁺, Ba²⁺, Cs⁺

Cs+ > Ba²⁺ > Sr²⁺

Cs+ has the biggest size, because its more downward (compared to Sr2+) and more to the left (compared) ot Ba2+.

Sr2+ has the smallest size because it's more upwords (compared to Cs+ and Ba2+)