Question

choose the element with the larger atoms from each of the following pairs. match the words in the left column to the appropriate blanks in the sentences on the right.

sn
si
br
ga
bi
se
unable to be determined based on periodic properties alone

between sn and si, the element with the larger atoms is
between br and ga, the element with the larger atoms is
between sn and bi, the element with the larger atoms is
between se and sn, the element with the larger atoms is

Explanation:

Atomic radius generally increases down a group (more electron shells) and decreases across a period (increasing nuclear charge pulls electrons closer).

1. Sn is below Si in Group 14, so Sn has larger atoms.
2. Ga is to the left of Br in Period 4; atomic radius decreases across a period, so Ga has larger atoms.
3. Sn (Group 14, Period 5) and Bi (Group 15, Period 6): Bi is one period lower but one group to the right. The period trend (increasing size down a group) outweighs the period trend, so Bi has larger atoms.
4. Se (Group 16, Period 4) and Sn (Group 14, Period 5): Sn is one period lower and two groups to the left; both trends make Sn have larger atoms.

Answer:

Between Sn and Si, the element with the larger atoms is Sn
Between Br and Ga, the element with the larger atoms is Ga
Between Sn and Bi, the element with the larger atoms is Bi
Between Se and Sn, the element with the larger atoms is Sn