Question

so lets see if you remember that important concept. determine the number of valence electrons for each of the following elements. helium has fill in blank valence electrons. sulfur has fill in blank valence electrons magnesium has fill in blank valence electrons. carbon has fill in blank valence electrons

Explanation:

Step1: Determine valence electrons for Helium

Helium (\(He\)) has an atomic number of \(2\). Its electron configuration is \(1s^{2}\). Since it has a full outer shell (the first shell can hold a maximum of \(2\) electrons), it has \(2\) valence electrons.

Step2: Determine valence electrons for Sulfur

Sulfur (\(S\)) has an atomic number of \(16\). Its electron configuration is \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{4}\). The outer shell is the third shell (\(n = 3\)), and the number of electrons in the outer shell (\(3s^{2}3p^{4}\)) is \(2 + 4=6\). So sulfur has \(6\) valence electrons.

Step3: Determine valence electrons for Magnesium

Magnesium (\(Mg\)) has an atomic number of \(12\). Its electron configuration is \(1s^{2}2s^{2}2p^{6}3s^{2}\). The outer shell is the third shell (\(n = 3\)), and the number of electrons in the outer shell (\(3s^{2}\)) is \(2\). So magnesium has \(2\) valence electrons.

Step4: Determine valence electrons for Carbon

Carbon (\(C\)) has an atomic number of \(6\). Its electron configuration is \(1s^{2}2s^{2}2p^{2}\). The outer shell is the second shell (\(n = 2\)), and the number of electrons in the outer shell (\(2s^{2}2p^{2}\)) is \(2+ 2=4\). So carbon has \(4\) valence electrons.

Answer:

Helium has \(2\) valence electrons.
Sulfur has \(6\) valence electrons.
Magnesium has \(2\) valence electrons.
Carbon has \(4\) valence electrons.