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prairie st chm110
prairie state chem110 chap 2 1-28
Question | Answer |
---|---|
Law of Conservation of Mass (Lavoisier) | "in a chemical reaction, matter is neither created or destroyed.Mass of reactants = Mass of products |
Indivisible | Matter is composed of small indestructable particles (ATOMS)(Leucippus ? Democritus) |
Divisible | Matter is composed of some combo of air, earth, water, fire.Aristotle / Plato |
Law of Definite Proportions (Proust) | Elements combine in diffinate mass ratios to form compounds. No matter what the source the compound components are the same |
Law of Multiple Proportions (Dalton) | when two elements A&B form a 2 differnt compound that the ratio of teh elements will be a small whole number.For example, carbon and oxygen react to form CO or CO2, but not CO1.3 |
Proton | mass 1.673x10*24, nucleus, charge + |
Neutron | mass 1.673x10*24, nucleus, charge o |
Electron | Mass 9.110x10*28 (very light) outside nucleus charge - |
What defines an element | The number of protons that it has |
Cations | positively charged atoms |
Anions | negativley charged ions |
Isotopes | atoms of the same element that have different number of neutrons |
Percent of natural abundance | refers to the abundance isotopes of a chemical element as naturally found on a planet. The relative atomic mass (a weighted average) of these isotopes is the atomic weight listed for the element in the periodic table |
35 cl17 | mass# 35 +p=17 E=17 N=18 |
Cl-37 | mass# 37, P=17 E=17 N=20 |
Periodic Law (Mendeleev) | When elements are arranged in order of increasing mass certain sets of properties recur periodically. |
Metals | good conductor of heat / elec., lose electrons during chemical rxns.,left on periodic table. |
Nonmetals | poor conductor of heat / elec., loss electrons during chemical rxns, right on periodic table. |
Metalliods | Know as semiconductors, they show mixed properties. |
Alkali metals | Group 1A very reactive (H2,Li,Na) |
Alkaline earth metals | Group 2A Fairly reactive (Mg,Ca,Sr) |
Halogens | group 7A VERY reactive nonmetals (Cl2,F2,Br2) |
Noble gasses | Chemically inert gasses Unreactive (He,Ne,Ar) |
Main group metals | Tends to LOSE electrons, forming cations with the same # of electrons as the nearest noble gas |
Main group nonmetals | tends to GAINS electrons , forming an anion with the same number of electrons as the nearest noble gas |
Mass spectrometry | used to measure the masses of atoms and the percentage of isotopes of an element. |