Term | Definition |
matter | anything that has mass and takes up space |
mass | a measure of the amount of matter in an object; is not affected by the gravitational forces on objects |
element | a substance that cannot be separated or broken down into simpler substances by chemical means |
atom | the smallest unit of an element that maintains the chemical properties of that element |
nucleus | in physical science, an atom's central region, which is made up of protons and neutrons |
proton | a subatomic particle that has a positive charge and that is located in the nucleus of an atom |
neutron | a subatomic particle that has no charge and that is located in the nucleus of an atom |
atomic number | the number of protons in the nucleus of an atom |
mass number | the sum of the number of protons and neutrons in the nucleus of an atom |
electron | a subatomic particle that has a negative charge |
orbital | a region in an atom where there is a high probability of finding electrons |
isotope | an atom that has the same number of protons as other atoms of the same element do but that has a different number of neutrons |
compound | a substance made up of atoms of two or more different elements joined by chemical bonds |
chemical bond | the attractive force that holds atoms or ions together |
covalent bond | a bond formed when atoms share one or more pairs of electrons |
molecule | a group of atoms that are held together by chemical forces |
ion | an atom, radical, or molecule that has gained or lost one or more electrons and has a negative or positive charge |
ionic bond | the attractive force between oppositely charged ions, which form when electrons are transferred from one atom to another |