What trend does the atomic radius follow along a period on the periodic

table?

A. The atomic radius gets smaller the farther right it appears on the

periodic table.

B. The atomic radius gets larger the farther right it appears on the

periodic table.

C. The atomic radius increases as the number of protons increases

across the table.

D. The atomic radius stays constant across the periodic table.

The atomic radius gets smaller the farther right it appears on the

periodic table.

Explanation:

Number of protons is increasing across the period so electrostatic attraction between the positive nucleus and the valence electrons increases and electrons are drawn close to the positive nucleus. This increases nuclear charge and so atomic radii gets smaller.

Also, the atomic radii size also depend on Electron - electron repulsion and shielding of the outermost valence electrons by the inner-most energy levels for the positive nucleus and number of energy levels.

Across the period, the electron-electron repulsion does not increase but there is increasing nuclear charge. The valence electrons are added to same energy level so electron shielding of the positive nucleus by the inner electrons is the same across the period.