Question

example #1: atomic radii

1. which of the following elements will have the smallest atomic size?

a) c
b) n
c) o
d) f

1. which of the following elements in group 2 will have the largest atomic size?

a) be
b) mg
c) sr
d) ba

1. which of the following elements will have the largest atomic size?

a) al
b) cl
c) br
d) mg

Explanation:

Step1: Recall atomic - size trends

Atomic size decreases across a period (left - to - right) due to increasing effective nuclear charge.

Step2: Analyze elements in question 1

C, N, O, and F are in the same period. F is the right - most element among them. So, F has the smallest atomic size.

Step3: Recall group - size trend

Atomic size increases down a group due to the addition of electron shells.

Step4: Analyze elements in question 2

Be, Mg, Sr, and Ba are in Group 2. Ba is the bottom - most element, so it has the largest atomic size.

Step5: Analyze elements in question 3

Among Al, Cl, Br, and Mg, Br has more electron shells compared to Al, Cl, and Mg. So, Br has the largest atomic size.

Answer:

1. d) F
2. d) Ba
3. c) Br