Question

An aluminum cation is smaller than the aluminum atom because it has fewer occupied energy levels. True false

Answer 1

Answer: The given statement is true.

Explanation:

Atomic number of aluminium is 13 and in order to attain stability aluminium loses 3 electrons. As a result, neutral aluminium atom converts into $Al^{3+}$ ion.

Thus, due to loss of electrons aluminium cation is smaller than neutral aluminium atom.

Therefore, the statement an aluminum cation is smaller than the aluminum atom because it has fewer occupied energy levels, is true.

Answer 2

The molecules or atoms that are formed by gain or loss of one or more valence electrons are said to be ions.

When atom loss one or more valence electrons, results in formation of cation whereas when atom gain one or more valence electrons, then formation of anion occurs. Cations carry positive charge and anions carry negative charge.

In general, cations are smaller than the neutral atoms from which they are formed and anions are larger than the neutral atoms.

As cations are smaller than the related neutral atoms because the valence electrons are lost which are farthest away from the nucleus. After that, taking more electrons distant from the cation results in reduction of radius of the ion.

Thus, aluminium cation consist of few electrons which results in fewer occupied energy levels by the electrons further results in reduction of radius i.e. smaller size.

Hence, given statement is true i.e. aluminium atom is larger than the aluminium cation as cation has fewer occupied energy levels.