which metalloid has five valence electrons in the fourth electron shell?\no antimony\no germanium\no…

Answer:

D. arsenic

Explanation:

Step1: Recall metalloid elements

Metalloids include boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), polonium (Po), astatine (At).

Step2: Analyze electron - shell and valence - electron information

We want an element with 5 valence electrons in the fourth electron shell. The electron configuration of arsenic (As) is [Ar] 4s²4p³, which means it has 5 valence electrons (2 in 4s and 3 in 4p) in the fourth electron shell. Antimony has 5 valence electrons but in the fifth electron shell. Germanium has 4 valence electrons in the fourth electron shell. Selenium is a non - metal and not a metalloid.