Question

fill out the table below based on the periodic table and the electron configurations given:
electron configuration

• 1s² 2s² 2p⁶ 3s²
• 1s² 2s² 2p⁶ 3s² 3p⁶

element
total # of electrons

of valence electrons

Explanation:

Step1: Calculate total electrons

For \(1s^{2}2s^{2}2p^{6}3s^{2}\):
Sum the exponents: \(2 + 2+6 + 2=12\)
For \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}\):
Sum the exponents: \(2+2 + 6+2+6 = 18\)

Step2: Identify elements

Using periodic table, element with 12 electrons is \(Mg\) (Magnesium), element with 18 electrons is \(Ar\) (Argon)

Step3: Find valence electrons

For \(Mg\) (\(1s^{2}2s^{2}2p^{6}3s^{2}\)), valence shell is \(3s\), valence electrons \(= 2\)
For \(Ar\) (\(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}\)), valence shell is \(3s\) and \(3p\), valence electrons \(= 2 + 6=8\)

Answer:

Electron Configuration	Element	Total # of Electrons	# of Valence Electrons
\(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}\)	\(Ar\)	\(18\)	\(8\)