Question

Which characteristics determine an element's reactivity?
A. valence electrons and group
B. electronegativity and period
C. valence electrons and electronegativity
D. group and period

Answer 1

The reactivity of an element is primarily determined by its valence electrons and the group it belongs to in the periodic table. As elements within the same group often share similar properties due to having the same number of valence electrons, this influences their reactivity.

Therefore, the correct answer is:
**A. valence electrons and group**.