| A | B |
|---|
| nucleus | the center on an atom |
| periodic table | a chart showing all the elements |
| atom | the smallest particle of an element |
| electron | a negatively charged particle |
| proton | a positively charged particle |
| physical change | a change where a new substance is NOT formed |
| atomic number | the number of protons or electrons |
| molecule | atoms bonded together form this |
| eight | this is the number of electrons in a stable atom |
| chemical change | a change where new substances are made |
| neutron | a particle in an atom with a neutral or no charge |
| mass number | number of protons + the number of neutrons |
| group | up and down column that explains the number of valence electrons |
| period | a horizontal group that explains the number of energy levels |
| subatomic particles with a relative mass of one | protons and neutrons |
| subatomic particle with a relative mass of 0 | electrons |
| an element with a mass number of 16 has what? | a total of 16 protons + neutrons |
| atoms with same atomic number but different atomic mass | isotope |
| noble gases | elements that have full valence shells and are not reactive |
| Why ice floats. | Ice is less dense than water. |
| a mixture in which different samples are not necessarily made up of exactly the same porportions | heterogeneous mixture |
| a mixture that contains more than one type of matter and is the same throughout | homogeneous mixture |
| a substance that contains only one kind of matter | element |
| substances made up of two or more elements that cannot be separated by physical means | compound |
