Question

which element has the same number of valence electrons as the element in the diagram?
3s
2p
2s
1s
argon
cesium
calcium
magnesium

Explanation:

Step1: Determine valence electrons of the element in the diagram

Valence electrons are in the outermost shell. Here, the outermost shell is \(3s\) with \(1\) electron.

Step2: Determine valence electrons of each option

• Argon: Electron configuration \([Ne]3s^{2}3p^{6}\), valence electrons \(8\).
• Cesium: Electron configuration \([Xe]6s^{1}\), valence electrons \(1\).
• Calcium: Electron configuration \([Ar]4s^{2}\), valence electrons \(2\).
• Magnesium: Electron configuration \([Ne]3s^{2}\), valence electrons \(2\).

Answer:

Cesium