Magnesium has an atomic number of 12, so there are 12 protons in any atom of this element. The number of protons do not change if it is an isotope of an element.
20 electrons
42 electrons
Two electrons from each element are shared; the total is four electrons.
6 valence electrons
3 valence electrons
8 electrons
16 electrons
20 electrons
97 electrons
4 electrons.
6 electrons
4 electrons, 2 valence electrons
Both those atoms are Magnesium but the second one is Magnesium25 not Magnesium 24 (standard Magnesium). Both have 12 protons and 12 electrons. Their charges are the same and their weights are the same.
There are 16 electrons in an O2 molecule. Each oxygen atom contributes 8 electrons, totaling 16 electrons in the molecule.
Germanium has 32 electrons.
Xenon has 54 electrons.
Argon has 18 electrons.