| A | B |
|---|
| compound | the result of a chemical change, forms when 2 or more elements combine, has new properties |
| energy level | an area around the nucleus of an atom |
| maximum number of electrons | 2, 8, 18, 32, 50 |
| electrons fill the energy levels in __________ | order |
| 3 ways atoms join together | share, lend, or borrow electrons that are in their outermost energy level |
| An atom becomes more ________ when its outermost energy level is filled. | stable |
| Table salt is made of... | sodium and chlorine |
| When an atom loses an electron it will have a... | positive charge. |
| When an atom gains an electron it will have a ... | negative charge. |
| ion | an atom that has either a poitive or a negative charge. |
| chemical bond | the attractive force that holds atoms together |
| chemical formula | a way to write the kinds and numbers of atoms in a compound |
| subscript | small number below the element symbol, tells the number of atoms of an element in a compound |
| If no subscript number is given after the symbol of an element, the compound has ______ atom of that element | only one |
| Na | sodium |
| H | hydrogen |
| C | carbon |
| O | oxygen |
| radical | group of two or more atoms that acts like one atom |
| During a chemical reaction, the atoms in a _________ stay together. | radical |
| characteristics of acids | sour taste, contain hydrogen, react with metals |
| examples of acids | vinegar, soft drinks, gastric juice, citrus fruits, etc. |
| characteristics of bases | bitter taste, contain the OH radical, slippery feel |
| examples of bases | antacids, soaps, cleaners, mortar |
| indicator | a substance that changes color when in an acid or a base |
| pH | a number that tells whether a substance is an acid or a base |
| pH of neutral substances | 7 |
| pH of acids | less than 7 |
| pH of bases | more than 7 |
| MgS | magnesium sufide |
