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| Greek philosopher - believed atoms were the smallest piece of matter | ||
| Developed Atomic Theory in 1803 and performed experiments to confirm the existence of atoms. | ||
| discovered negatively charged particles (electrons) using a cathode ray tube. | ||
| Developed "Plum Pudding" model of the atom in 1897 / discovered electrons with cathode ray tube | ||
| Found nucleus in 1908 by shooting positively charged particles through a thin piece of gold foil | ||
| Develops model of atom where electrons move in definite orbits around the nucleus. He's Danish! | ||
| basic unit of matter | ||
| the center of an atom | ||
| positively charged subatomic particle in the nucleus of an atom | ||
| negatively chraged subatomic particle moving around outside of the nucleus | ||
| neutral subatomic particle located in the nucleus | ||
| Worked by trial and error to try and change one substance into another | ||
| Contributed to the law of conservation of matter: the mass of the reactants equals the mass of the products. | ||
| made the periodic table. | ||
| the number of protons in an atom - used on the periodic table | ||
| total mass of the atom in AMU - (sum of neutrons & protons) | ||
| shorthand for atomic mass units - Hydrogen's mass in AMU is 1 | ||
| a region around the nucleus where electrons are - a "fuzzy" orbit | ||
| shorthand way to represent the valence electrons of a given atom | ||
| an atom that differs in the number of neutrons and thus has a different mass | ||
| an electron in the outermost energy level of an atom | ||
| specific areas around the nucleus in which electrons are likely to be found | ||
| rows on the periodic table - all elements in each row have the same number of electron shells | ||
| columns on the periodic table - all element in each column have the same number of valence electrons | ||
| elements on the periodic table with high luster, good electrical conductivity, malleability, and loosely held valence electrons | ||
| elements on the periodic table with low luster, poor electrical conductivity, tending to be brittle, tightly held valence electrons | ||
| elements on the periodic table with properties of metals and nonmetals. conductivity in between metals and nonmetals - some are semiconductors | ||
| element family - explosive in water, very reactive, metallic | ||
| element family - found in earth's crust, form bases in solution, metallic | ||
| element family - middle of periodic table, metallic | ||
| element family - 7 valence electrons, nonmetals, reactive | ||
| element family - stable & unreactive, full outer shells | ||
| element family - rare earth elements, inner transition metals | ||
| element family - inner transition elements, radioactive, heavy and unstable | ||
| an element that doesn't conduct electricity as well as a metal, but conducts electricity better than a nonmetal. Example - silicon | ||
| distance from the center of an atom to its outmost edge. Increases from left to right on the periodic table | ||
| chemists used the ___ of elements to sort them into groups | ||
| atoms react by gaining or losing electrons so as to acquire the stable electron structure of a noble gass, usually eight valence electrons | ||
| an atom or group of atoms that has a positive or negative charge | ||
| the electrostatic attraction that binds oppositely charged ions together | ||
| shows the kinds and numbers of atoms in the smallest representative unit of a substance | ||
| most ionic compounds are _____ solids at room temperature | ||
| ionic compounds can ___ an electric current when melted or dissolve in water | ||
| What is the net charge of an ionic compound? | ||
| basic name for a force of attraction that holds atoms together | ||
| formed when atoms share electrons | ||
| solid mixtures made by dissolving metals in other metals | ||
| The amount of energy used to remove an electron from an atom | ||
| bonds that involve two / three shared pairs of electrons | ||
| compound that consists of positive and negative ions; i.e. sodium chloride | ||
| a neutral group of atoms joined by covalent bonds | ||
| covalent bond in which electrons are shared unequally | ||
| valence electrons are share equally in a covalent bond | ||
| an attraction -between particles or atoms- that make up a molecule or compound (ionic / covalent bonds - also known as interparticle force) | ||
| weaker forces that hold different molecules near each other | ||
| a repetitive geometric arrangement of points in space about which atoms, ions, or molecules are arranged to form a 3D structure | ||
| an everyday name for an ionic compound that is composed of cations bonded to anions | ||
| high melting points, soluble in water, no odor, usually solid, hard, conducts electricity | ||
| lower melting points, solid liquid or gas, softer, doesn't conduct electricity | ||
| intramolecular or interparticle force that helps form ionic bonds between cations & anions |
