| A | B |
|---|
| law of definite proportions | specific substances always contain elements in the same ratio by mass. |
| law of multiple proportions | the ratio of masses of one element that combine with a constant mass of another element can be expressed in small whole numbers |
| anode | the positive electrode |
| cathode | the negative electrode |
| cathode rays | rays in the tube moving from the cathode to the anode |
| isotopes | atoms of the same element that differ in masses |
| isotopes! | have the same number of protons but a different number of neutrons |
| atomic number | the number of protons (Z) |
| nuclide | a particular kind of atom containing a definite number of protons and neutrons |
| nucleons | protons and neutrons that make up the atomic nucleus |
| mass number | the total number of nucleons in an atom (A) |
| radioactivity | phenomenon of rays being produced spontaneously by unstable atomic nuclei |
