Question

1. how many electrons does an atom of group 2, period 3 have? clear all 12 3 13 10

Explanation:

Step1: Recall periodic - table electron rules

Elements in Group 2 have 2 valence electrons. The period number indicates the energy level. For a period 3 element, we consider the electron - filling order. The atomic number of an element in Group 2, Period 3 is 12 (magnesium).

Step2: Use atomic number for electron count

The number of electrons in a neutral atom is equal to its atomic number. So, an atom of Group 2, Period 3 has 12 electrons.

Answer:

12