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Chemistry Ch.3+4
| Term | Definition |
|---|---|
| Most abundant element on Earth | Oxygen |
| Most abundant element in the human body | Oxygen |
| Democritus model | Called smallest possible particle of matter an element |
| Aristole+Greeks | 5 elements (earth, water, fire, air, eather) |
| Alchemists | Thought elements could be changed into different elements |
| Law of constant composition | Given compound always has same proportion of elements |
| Dalton’s atomic theory | Elements are made of tiny particles -all atoms of an element are identical -atoms of 1 element differ from those of others -atoms combine in specific ways -atoms are indivisible in chemical processes |
| Thompson model | -positive and negative charges floating around -discovered electrons(cathode ray tube) -plum pudding model |
| Marie Curiel | -2 Nobel prizes -coined term “radiation” -discovered 2 elements |
| Bohr model | -atom is mostly empty space -electrons orbit |
| James chadwick | Discovered neutron |
| Electron | Negative(-1 charge) |
| Neutron | Neutral(no charge) |
| Proton | Positive(+1 charge) |
| Atomic # | Number of protons(usually equal to # of electrons) |
| Atomic mass | # of protons and neutrons |
| Isotope | Same element w/ different # of neutrons |
| Allotrope | Same element or isotope w/ different formation |
| Dimitri Mendeleev | Designed first periodic table |
| Mosely | Developed first modern periodic table |
| Groups or families(on periodic table) | Columns(up and down) |
| Periods(on periodic table) | Rows(sideways) |
| Ion | Atom that has gained or lost electrons |
| Positive ion | Atom that has lost electron(metals) |
| Negative ion | Atom that has gained electron(non-metal) |
| Oxidation # | Combining ability of an element |
| Chemical bond | Force that holds atoms together in a compound |
| Ionic bond | Electrons are transferred creating opposite charges that attract |
| Chemical formula | Indicates the elements in a compound and the ratio of those elements |