Question

what determines the chemical properties of an element?
o atomic number
o number of electron shells
o number of valence electrons
o physical state at room temperature

Explanation:

Valence electrons are the out - most electrons of an atom. They participate in chemical reactions as they are involved in bond - formation. So, the number of valence electrons determines an element's chemical properties. The atomic number determines the identity of the element, the number of electron shells affects the size and some properties but not directly the chemical reactivity like valence electrons do, and the physical state at room temperature is a physical property, not a determinant of chemical properties.

Answer:

C. number of valence electrons