Sodium and Chlorine are both elements, so the only contain one type of atom.
Is this true or false?
True

the answer would be a

it's c. elements are placed in rows based on how may valencies electrons have.

the number of protons in the nucleus of a given element. has slight luster and conducts electricity at high temperatures like metal.but like a nonmetal,boron is brittle and does not conduct electricity well at low temperatures. in graphite, carbon is a soft,brittle solid.it is reflective,ductile,or malleable.