| A | B |
|---|
| Matter | Occupy space and has mass |
| Chemical Elements | Cannot be changed by ordinary chemical reactions |
| Atom | The smallest unit of an element |
| Protons | Carry + charge, found in the nucleus |
| Neutrons | Carry no charge, found in the nucles |
| Electrons | Carry - charge, found in orbits arround the nucleus |
| Atomic number | Corresponds to the number of protons |
| Atomic weight | Protons+Neutrons |
| Chemical bonds | Forces of attraction between 2 atoms that keep them together |
| Ionic bonds | Formed between a - and a+ ion |
| Cation | +ively charged atom, formed when an atom lose an electron to another atom |
| Anion | -ively charged atom, formed when an atom gain an electron from another atom |
| Covalent bond | Formed by the sharing of electrons between two atoms |
| Molecule | Two or more atoms combined |
| Single covalent bond | 1 electron pair shared |
| Double covalent bond | 2 electron pairs shared |
| Hydrogen bond | Formed between the hydrogen of one molecule and a N or O of another molecule |
| Acid | Substance that release H+ when dissolved in water |
| Base | Substance that release OH- when dissolved in water |
| pH | H+ ions concentration |
