Term | Definition |
Atom | a small particle that is the building block of matter |
Atom | the smallest piece of an element that still represents that element |
Electron | a negatively charged particle that occupies the space in an atom outside the nucleus |
Nucleus | the region in the center of an atom where most of an atom’s mass and positive charge are concentrated |
Proton | positively charged particle in the nucleus of an atom |
Neutron | a neutral particle in the nucleus of an atom |
Electron Cloud | the region surrounding an atom’s nucleus where one or more electrons are most likely to be found |
Element | a substance that consists of only one type of atom |
Molecule | two or more atoms that are held together by covalent bonds and act as a unit |
Compound | a substance containing atoms of two or more different elements chemically bonded together |
Chemical Bond | a force that holds two or more atoms together |
Crystal | a repeating three-dimensional pattern of atoms |
Physical Property | a characteristic of matter that you can observe or measure without changing the identity of the matter |
Chemical Property | the ability or inability of a substance to combine with or change into one or more new substances |
Physical Change | a change in the size, shape, form, or state of matter that does not change the matter’s identity |
Chemical Change | a change in matter in which the substances that make up the matter change into other substances with different chemical and physical properties |
Reactant | a starting substance in a chemical reaction |
Product | a substance produced by a chemical reaction |
Law of Conservation of Mass | states that the total mass of the reactants before a chemical reaction is the same as the total mass of the products after the chemical reaction |