A) An element is the fundamental unit of an atom.
B) An element is composed of atoms that are joined together by ionic and covalent bonds.
C) An atom is composed of different elements that are joined together by ionic and covalent bonds.
D) An atom is the smallest unit of an element that demonstrates all of the properties of that element.

A) Electrons are located in shells around the nucleus.
B) Electrons are attracted to each other because they have the same charge.
C) In order for an electron to move closer to the nucleus, it must absorb energy.
D) The innermost electron shell has the most potential energy.
E) As an electron moves to a shell further from the nucleus, it loses energy.

A) 17; 18
B) 18; 17
C) 17; 35
D) 35; 17
E) 18; 18