The number of valence electrons in an element with electron configuration 1s2 2s2 2p6 3s2 3p4 is

The number of valence electron in the element is 6 electrons

Valence electron(s) are the electrons located on the outermost shell of an atom.

From the question given above, we obtained:

Electronic configuration => 1s² 2s²2p⁶ 3s²3p⁴

The valence shell is => 3s²3p⁴

Total electron in valence shell = 2 + 4

Total electron in valence shell = 6 electrons

Therefore, the number of valence electron in the element is 6 electrons.

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The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.

Answer(2) electrons;