| A | B |
|---|
| Anything that has occupies space and has mass. | Matter |
| A substance that cannot be split into simpler substances by ordinary chemical reactions. | Element |
| Official abbreviation that represents an element. | Chemical symbol |
| Elements (4) that make up 96% of the body by weight. | Carbon, hydrogen, oxygen, nitrogen. |
| Smallest unit of matter having the characteristics of a particular element. | Atom |
| Subatomic particle having a positive charge. | Proton |
| Subatomic particle having a neutral charge. | Neutron |
| Subatomic particle having a negative charge. | Electron |
| Which 2 subatomic particles are located in the nucleus? | Proton and neutron. |
| Which 2 subatomic particles have a mass of approximately 1 amu each? | Proton and neutron. |
| The dense central core of an atom is the ___. | Nucleus |
| Which 2 subatomic particles are located in the nucleus? | Proton and neutron. |
| Which subatomic particle is considered weightless? | Electron |
| Which subatomic particle is found outside the nucleus? | Electron |
| In the regular form of each atom, the number of ___ and ___ is the same. | Protons and electrons. |
| The number of ___ in the nucleus is what makes the atoms of one element different from atoms of another. | Protons |
| On the periodic table, the atomic number represents the number of ___ in the atoms of the element. | Protons |
| If an atom has a number of neutrons that varies from the number considered normal, that atom is called an ___ of the element. | Isotope |
| Isotopes have the same ____ number as regular atoms of the element, but the ___ number will be different. | Atomic number is same; mass number will be different. |
| Unstable isotopes tend to decay and give off energy called ___. | Radiation (radioactivity) |
| The outermost shell of an atom that contains any electrons is called the ___ shell. | Valence |
| Atoms that naturally have completely filled outermost shells are ____. | Inert--do not participate in chemical reactions. |
| If the outermost shell of an atom contains only a few electrons, that atom will be most likely to ___ electrons and become ___ in charge. | Lose (donate) and become positive in charge. |
| If the outermost shell of an atom is almost but not quite filled with electrons, that atom will be most likely to ___ electrons and become ___ in charge. | Gain and become negative in charge. |
| If the outermost shell of an atom is half-filled with electrons, that atom is most likely to ___ electrons. | Share |
| The 3 electron shells closest to the nucleus have spaces for ___, ____, and ___ electrons. | 2 8 8 |
| An electrically charged atom or group of atoms with an unpaired electron in its outermost shell is called a ___ ____. | Free radical |
