| A | B |
|---|
| neutron | atomic particle with a neutral charge; found in the nucleus; about the same size as a proton |
| atomic number | the number of protons of an element (atom); identifies an element on the Period Table of Elements; also help us know the number of electrons of an element (atom) |
| atomic mass number | the number representing the mass of an atom; the number of protons plus the number of neutrons of an element |
| metals | one of the main groups of elements; found on the left side of the Periodic Table of Elements; largest group of elements |
| nonmetals | one of the main groups of elements; found toward the right side of the Periodic Table of Elements |
| semimetals | one of the main groups of elements; have some characteristics of metals and some characteristics of nonmetals; found along the stair-step line on the right side of the Table of Elements |
| noble gases | one of the main groups of elements; are very stable and usually do not form compounds; found in the far right column on the Periodic Table of Elements |
| subscript | numbers written with the symbols in a chemical formula; written slightly below the symbols in the formula; tells how many atoms of the element are present |
| family | elements on the Periodic Table of Elements with similar properties; a column on the Periodic Table; also called a chemical family or a group |
| organic compounds | compounds that contain carbon; make up all living things or things that were once alive |
| examples of physical properties | color; size; odor; density' melting/freezing point; boiling point |
| examples of chemical properties | ability to burn; ability to rust; reacts with metals; reacts with bases; reacts with acids |
