9. When two compounds are made up of the same number and kind of atoms, but differ in
their molecular structure they are known as:
A) isotopes
B) homologs
C) isomers
D) hydrocarbon

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.