Chem Midterm
About this set
Created by:
mortensen04 on January 27, 2009
Subjects:
Log in to favorite or report as inappropriate.
Order by
43 terms
Terms | Definitions |
|---|---|
 length | meters |
| time | seconds |
| mass | kilograms |
| amount of substance | mole |
| temperature | kelvin |
| luminous intensity | candela |
| electric current | ampere |
| signs of chemical changes | gas forming, change in color, precipitate, flamability |
| endothermic | energy being absorbed Na------> Na+E |
| exothermic | energy being released Na------> Na-E |
| heat | the energy transferred between objects that are different temperatures |
| temperature | a measure of how hot something is |
| specific heat | the amount of energy need to heat an element in joules |
| formula for specific heat | cp= q/(m* ΔT) q= joules m=mass? ΔT= change in temp |
| the scientific method | a series of steps followed to solve problems |
| theory | an explanation for some phenomenon |
| law | tells how things work |
| law of definite proportions | a chemical compound always contains the same elements in exactly the same proportions |
| law of multiple proportions | when two elements combine to form two or more compounds, the mass of one elements that combines with a given mass of of the other is in the ratio of small whole numbers |
| daltons atomic theory | 1) all matter is made of atoms that can't be divided, created, or destroyed. 2) atoms of an element are identical 3) atoms of different elements are different 4) atoms of different elements combine in ratio. 5) In chemical reactions, atoms are combined, separated, or rearranged, but never destroyed or changed |
| subatomic particles | the particles that make up an atom |
| isotope | an atom that has the same number of protons but different amount of electrons |
| Rutherfords gold foil experiment | he discovered the atomic theory from it, electrons move like particles |
| Bohr's hydrogen atom | discovered the quantum numbers with it, particles act like a wave |
| principal | n, energy level, n=1,2,3... |
| sublevel | l, sublevel, l=0---->n-1 |
| magnetic | m,orientation of electron cloud |
| spin | s, direction of electron cloud, s= +1/2, -1/2 |
| quantum | a number that specifies the properties of electrons |
| p orbitals | x, y, and z |
| molar mass | the mass in grams of 1 mol of substance |
| avogadro's number | 6.02*10_23 |
| periodic law | the repeating physical and chemical properties of elements change periodically with their atomic number |
| Moseley | arranged periodic table by atomic number |
| Mendeleev | arranged first periodic table by atomic mass |
| ionization energy | the energy required to remove an electron from an atom or ion |
| electron shielding | electrons in lower energy levels block the effective positive charge of the nucleus from valence electrons |
| bond radius | half the distance from center to center of two like atoms that are bonded |
| electronegativity | an atom's attraction for electrons in a chemical bond |
| periodic trend for ionization energy | it decreases down because the smaller atoms require more energy to remove electrons and in larger atoms the electrons are farther away from the nucleus and require less energy to remove. It increases left to right because as the charge increases and size decreases, the atom holds in to the electrons tighter and the atom requires more energy to move |
| periodic trend for atomic radii | it decreases left to right because as the nuclear charge increases and the electrons are added to the same energy level, the nucleus holds the electrons tighter so the atom is smaller. It increases down because the energy level increases. |
| Why are metal ions different from metal atoms | the metal ion is smaller because the protons are now attracting fewer electrons, so they hold them tighter |
| why are nonmetals ions different from metal ones | the nonmetal ion is bigger because it has the same amount of protons and more electrons |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.