Question

which diagram shows the relation between the atomic numbers (z) and the atomic radius (r) of elements in the same period? a b c d

Explanation:

Step1: Recall atomic - radius trend

As the atomic number (Z) increases across a period, the number of protons in the nucleus increases, and the effective nuclear charge increases. The electrons are pulled more strongly towards the nucleus, causing the atomic radius (r) to decrease.

Step2: Analyze the graphs

The graph that shows a decrease in the atomic radius (r) as the atomic number (Z) increases is a downward - sloping graph.

Answer:

A. The graph with a downward - sloping line as r decreases with an increase in Z.