| A | B |
|---|
| law of conservation says | mass cannot be created or destroyed in ordinary chemical or physical changes |
| law of conservation made simple is | mass of reactants=s mass of products |
| law of multiple proportions says | when two elements conbine to form compounds, the mass of one element that combines with other is always a ratio of small whole numbers |
| law of definite proportions says | a chemical compound always contains the same elements in exactly the same proportions by mass (weight) |
| law of definite proportion also says that | every molecule of a compound is made up of the same number and type of atoms, regardless of size of sample |
| nucleus | is the small area in center of an atom, containing protons and neutrons |
| cloud | is the area surrounding the the nucleus where electrons are found |
| typically, the cloud is | 10,000 times the radius of the nucleus |
| most of an atom is | empty space ( |
| orbitals | are the pathways in the cloud of an atom, where electrons can be found |
| subatomic particles | are the smaller parts that compose atoms |
| the two subatomic areas are | the cloud and nucleus |
| the three subatomic particles are | protons, electrons and neutrons |
| protons and neutrons contribute | most to an atom's mass |
| electrons in the cloud contribute | most to an atom's space/volume |
| the nucleus of an atom | is very heavy and very small |
| electrons are | very light (1 e = 1836 p = 1841 n) |
| the nucleus' size is 1/10,000 | of the radius of the whole atom ( like marble to football field) |
| picometer (pm) | is the unit used to express atomic radius |
| protons weigh almost 2000 times | the mass of an electron (but charge is equal) |
