Multiple Choice
How many valence electrons does a neutral nitrogen atom have?
2
views
9. Electrons in Atoms and the Periodic Table
Valence Electrons of Elements (Simplified)
Struggling with Introduction to Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
How many valence electrons does magnesium (Mg) have in its ground-state electron configuration?
A
6
B
1
C
8
D
2
Verified step by step guidance1
Identify the atomic number of magnesium (Mg), which is 12. This means magnesium has 12 electrons in its neutral ground state.
Write the ground-state electron configuration of magnesium by filling the orbitals in order of increasing energy: 1s, 2s, 2p, 3s, etc.
The electron configuration for magnesium is \$1s^2 2s^2 2p^6 3s^2$. The electrons in the outermost shell (highest principal quantum number) are the valence electrons.
Determine the valence shell for magnesium, which is the third shell (n=3), containing the \$3s^2$ electrons.
Count the number of electrons in the valence shell: there are 2 electrons in the \$3s$ orbital, so magnesium has 2 valence electrons.
1:55mWatch next
Master Valence Electrons of Elements (Simplified) Concept 1 with a bite sized video explanation from Jules
Start learningRelated Videos
Related Practice
Valence Electrons of Elements (Simplified) practice set
Problem sets built by lead tutorsExpert video explanations