How does calcium atomic radius compare to magnesium (Mg) radius and patssiuks (K) redius?

The radius of a calcium atom would be larger than that of a magnesium atom.

The radius of a calcium atom would be slightly smaller than that of a potassium atom.

Explanation:

Refer to a modern copy of the periodic table.

Calcium and magnesium are in the same column. They are in the same group (IUPAC group .)

Hence, atoms of calcium and magnesium would have similar effective nuclear charges. In other words, the attraction between a calcium atom nucleus and its valence electrons would be similar to that of magnesium.

However, calcium is in the fourth row of the periodic table (fourth period) while magnesium is in the third (third period.) A calcium atom would thus have four main shells with electrons. In contrast, a magnesium atom would only have three such main shells.

Despite the similar effective nuclear charge (effective attraction on the outermost electrons,) the radius of a calcium atom would be larger than that of a magnesium atom because of the extra main electron shell.

On the other hand, calcium and potassium are in the same row (same period.) A calcium atom and a potassium atom would both include four electron-filled main shells.

However, with one additional proton per atom, the effective nuclear charge of calcium atoms would be greater than that of potassium atoms. Hence, when compared to potassium nuclei, the nucleus of a calcium atom would pull its electron shells closer to the center. The radius of a calcium atom would thus be smaller than that of a potassium atom.

In general, atomic radius would generally become larger when moving down a column in the periodic table. On the other hand, atomic radius would general become smaller when moving towards the right-hand side of a row in the periodic table.

the temperature of the gas, in k, not celsius.