Fill in the blank: A group of atoms that are held together by chemical bonds is called a(n) _______.

Fill in the blank: The positively-charged center of the atom that contains protons and neutrons is called the _______.

Fill in the blank: Positively-charged particles found in the nucleus are called _______.

Fill in the blank: Neutral particles with no charge, found in the nucleus, are called _______.

Fill in the blank: Negatively-charged particles that surround the nucleus are called _______.

Fill in the blank: The area where electrons are likely to be found is called the _______.

Fill in the blank: Electrons found on the last level on the electron cloud in an atom are called _______.

Fill in the blank: Matter made of only one kind of atom and cannot be broken down into simple substances is called a(n) _______.

Fill in the blank: A chart that contains all known elements, their properties and symbols is called the _______.

Fill in the blank: Symbols used to represent elements on the periodic table are called _______.

Fill in the blank: The number used to identify elements, which also equals the number of protons in an element, is called the _______.

Fill in the blank: The sum of the number of protons and the number of neutrons in the nucleus of an atom is called the _______.

Fill in the blank: Atoms of the same element that have different masses (they have a different number of neutrons) are called _______.

Fill in the blank: When atoms of two or more elements chemically combine, they form _______.

Fill in the blank: A group of chemical symbols and numbers that represent the elements and the number of atoms of each element in a compound is called a _______.

Fill in the blank: When atoms of one or more substances rearrange to form one or more new substances, it is called a _______.

Fill in the blank: Group 1 elements that are the most reactive elements are called _______.

Fill in the blank: Elements that have properties of both metals and nonmetals are called _______.

Fill in the blank: Group 18 elements that do not chemically react with any other element are called _______.