Question

how many valence electrons does this atom have? ar4s²3d¹⁰4p³ 17 8 7 10

Explanation:

Step1: Identify valence shell

Valence electrons are in the outermost shell. Here, the outermost shell is \(n = 4\) (from \(4s\) and \(4p\))

Step2: Count electrons in valence shell

For \(4s^{2}\), the number of electrons is \(2\). For \(4p^{5}\), the number of electrons is \(5\).
Sum of electrons in valence shell: \(2 + 5=7\)

Answer:

7