Question

part 4 of 4
a transition metal in period 4, group 12.
a main group element in period 3, group 2.

Explanation:

For "A main group element in period 3, group 2"

To identify the element, we use the periodic table. Period 3 means the third row, and group 2 (main group, alkaline earth metals) in period 3 has the element with atomic number calculated as follows: period 3 elements have electron shells up to \(n = 3\), group 2 has 2 valence electrons. The electron configuration for period 3, group 2 is \(1s^2 2s^2 2p^6 3s^2\), which corresponds to magnesium (Mg).

Using the periodic table, period 4 is the fourth row, group 12 (transition metals, zinc group). The element in period 4, group 12 has electron configuration \(1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^2\), which is zinc (Zn).

Answer:

Magnesium (Mg)

For "A transition metal in period 4, group 12"