Question

instructions: in each question, list the elements from least to greatest atomic radius:

1. cesium (cs), potassium (k), sodium (na)
2. phosphorus (p), aluminum (al), magnesium (mg)
3. zinc (zn), oxygen (o), rubidium (rb)

Explanation:

4)

Step1: Analyze the group

These elements (Cs, K, Na) are in Group 1 (alkali metals). As we move down a group in the periodic table, the atomic radius increases because a new electron shell is added.

Step2: Compare their positions

Na is in the 3rd period, K in the 4th period, and Cs in the 6th period.
So the order from least to greatest atomic radius is \(Na

5)

Step1: Analyze the period

These elements (P, Al, Mg) are in the 3rd period. In a period, as we move from left to right, the atomic radius decreases because the nuclear charge increases (more protons attract the electrons more strongly).

Step2: Compare their positions

Mg is in Group 2, Al in Group 13, and P in Group 15.
So the order from least to greatest atomic radius is \(P

6)

Step1: Analyze the positions

O is in the 2nd period (smallest as it has fewer electron shells compared to the others). Zn is in the 4th period (d - block element), and Rb is in the 5th period (Group 1, alkali metal).

Step2: Compare atomic radii trends

As we move down the periodic table, atomic radius increases. Also, Rb (Group 1) has a larger radius than Zn (d - block in the same period as it has a less - effective nuclear charge in terms of shielding).
So the order from least to greatest atomic radius is \(O

Answer:

1. \(Na
2. \(P
3. \(O