| A | B |
|---|
| endothermic reaction | a chemical reaction that absorbs heat |
| exothermic | a chemical reaction that produces heat |
| chemical change | a process in which the substances involved are changed into a new substance |
| physical change | a process in which the substance or substances involved are physically changed but the susbstance itself stays the same |
| atomic mass | the sum of the number of protons and number of neutrons in a atom |
| atomic number | the number of protons in an atom |
| electrons | a negatively-charged component of an atom |
| neutrons | a neutrally-charged component of an atom |
| nucleus | the center of an atom that contains neutrons and protons |
| protons | a positively-charged component of an atom |
| bonding | atoms joining together with an attractive force that holds the atoms together |
| compounds | substances made up of more than one type of atom |
| covalent bond | bond produced through the sharing of electrons |
| ionic bond | bond produced by attraction of opposite charges |
| metallic bond | bond produced by metallic elements sharing electrons between themseleves |
| non-metal elements | elements that don't conduct heat or electricity well; are brittle and don't reflect light. They are: hydrogen, carbon, nitrogen,oxygen, phosphorus, sulfur, and selenium. |
| peptide bond | covalentbond produced when amino acids in proteins are joined together |
