An element's reactivity and other chemical properties are determined by the number of -

How many core electrons does the gallium atom possess?

Provide the number of valence electrons in the iron (III) ion.

Which of the following have their valence electrons in the same shell?

(b) How many valence electrons does a nitrogen atom possess?

(c) An atom has the electron configuration 1s²2s²2p⁶3s²3p². How many valence electrons does the atom have?

(a) True or false: An element's number of valence electrons is the same as its atomic number.

Consider the element silicon, Si. (c) Which subshells hold the valence electrons?