Question | Answer |
who founded the conservation of mass? | antione lavoiser 1787 |
conservation of mass | the products of a reaction always equals the mass of the reacting substances |
who found law of definite proportions | joseph proust 1797-1804 |
law of definite proportions | all samples of the same compound always contain the same proportions by mass of the component elements |
1808, Dalton's atomic theory (first 2) | 1) all matter is made up of atoms
2)all atoms of an element are identical in mass and in chemical properties. however atoms of different elements have different masses and properties. |
dalton's atomic theory (3 and 4) | 3)atoms aren't created or destroyed by chemical reaction
4) atoms combine in simple fixed whole number ratios to form compounds |
subatomic particles | smaller particle found inside of atom |
how many are known? how many have importance in chemical behavior? | 40 , 3 |
protons are....electrons are....neutrons are.... | positive, negative, neutral |
jj thompson contributions | "plum pudding" model of atomic structure. and finds electrons with cathode ray tubes experiment |
ernest rutherford contributions | gold foil experiment. finds nucleus |
nucleus | central core of atom which contains protons and neutrons; contributes most of mass of an atom |
the number of protons is the | atomic number |
the number of protons equals the number of | electrons |
isotope | an element that contains a specific number number of neutrons. the nucleus only has 1 proton |
mass number (A) | sum of protons and neutrons (N). count of number of particles in the nucleus |
isotope symbol | representation of mass number and atomic number of an isotope |
ion | when atom contains more or less electrons than protons. |
examples of naturally occurring ions | sodium and calcium |
what are the two types of ions | cation an anion |
cation | positively charged ion that contains fewer electron than the number of protons in the nucleus. ex calcium |
anion | negatively charged ion that contains more electrons than the number of protons in the nucleus. ex chlorine |
atomic mass unit | basic unit of mass atoms and molecules |
relative atomic mass | the average mass of an tom of an element taking into account the masses and the abundance of all the naturally occurring isotopes. (like hydrogen) |
periodic table | known elements arranged in columns and rows to emphasize periodic properties |
family or group | elements with similar properties in same vertical row. Labelled l - Vlll and letter A or B |
period | horizontal row of elements whose properties tend to vary in a regular fashion. labelled 1-7 |
stair step line | separates the metals (left) from the nonmetals (right) |
metalloid/semimetal | has physical properties resembling a metal but chemical reactivity more like that of a nonmetal. |
main group element (representative element) | any element in one of eight groups labeled with letter A |
transition metal | an element in any of 10 groups labelled with letter B |
inner transition metal | an element that s a lanthanide (atomic number 58 to 71) of a actinide (atomic number 90 to 103) |
alkali metal | group lA (excluding hydrogen)..reactive |
alkaline earth metal | group llA. less reactive than alkali metals |
halogen | group VllA |
noble gas | group VlllA. inert most stable of all elements. |
diatomic molecule | molecule consisting of two atoms. ex chlorine bromine hydrogen oxygen |