| A | B |
|---|
| chemistry is the study of | matter |
| substance | the same composition and properties |
| matter is made up of | atoms |
| atom | smallest unit of an element that retains it's properties |
| atoms contain 3 subatomic particles | protons, neutron, electrons |
| protons are | + |
| electrons are | - |
| neutrons are | neutral |
| protons are found in | the nucleus of an atom |
| neutrons are found in | the nucleus |
| electrons are found | outside the nucleus & arranged according to energy level |
| an element is identified by it's | symbol and atomic number |
| the atomic number is | = to the number of protons found in the nucleus |
| mass number | = to the number of nucleons ( protons + neutrons) |
| to find the number of neutrons in an atom | atomic no. - the mass no. of an element |
| isotopes | atoms of the same element that contain a different no. of neutrons |
| atomic mass | The atomic mass is the total mass of protons, neutrons and electrons in a single atom. |
| radio isotopes | artificially produced |
| ions | charged atoms |
| cation | ion with a positive charge + |
| anion | ion with a negative charge |
| valence electrons | outermost shell |
| periodic table | contains all known elements |
| periodshorizontal rows in the periodic table | periods |
| noble gases | have full valence shells and are inert |
