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29 Cards in this Set

  • Front
  • Back
Chemical reaction
The transformation of a substance or substances into one or more new substances
Law of conservation of mass
Mass is neither created nor destroyed during ordinary chemical reactions or physical changes.
Law of definite proportions
A chemical contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound
Law of multiple properties
If two or more different compounds are composed of the same two, then the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers
Daltons atomic theory
1- All matter is composed or extremely small particles called atoms
2- Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass and other properties
3- Atoms cannot be subdivided, created, or destroyed
4- Atoms of different element combine in simple whole-number ratios to form chemical compounds
5-In chemical reactions, atoms are combined, seperated, or rearranged
Scientific theory
theory that can be tested by experiments
Modern atomic theory
1-All matter is composed of atoms
2-Atoms of any one element differ in properties from atoms of another element remain unchanged.
the smallest particle of an element that still retains the chemical properties of that element
the very small region located at the center of the atom
Positively charged particle located in the nucleus
Neutrally charged particle located in the nucleus
Negatively charged particles which surround the nucleus
Subatomic particals
cathode ray tubes
Glass tubes which carried out experiments
nuclear forces
These short-range proton-neutron,proton-proton, and nuetron-neutron forces hold the nuclear particles together
Atomic number
The...of an element is the number of protons of each atom of that element
Atoms of the same element that have different masses
Hydrogen isotopes
Mass number
The .... is the total number of protons and neutrons that make up the nucleus of an isotope.
....general term for a specific isotope of an element
Atomic mass unit (amu)
1 amu is exactly 1/12 the mass of a carbon-12 atom
Average atomic mass
The weighted average of the atomic masses of the naturally occuring isotopes of an element
Mole (mol)
The amount of a substance that contains as many particles as there are atoms in exactly 12 grams of carbon-12
Avogadro's number
6.022x10^23- the number if particles in exactly one mole of a pure substance
molar mass
The mass of one mole of a pure substance
Mass to Moles (conversion)
1 mol/molar mass of element
Moles to mass (conversion)
Molar mass of element/ 1 mol
Moles to atoms (conversion)
6.022x 10^23 atoms/1 mol
Atoms to moles (conversions)
1 mol/ 6.022 x 10^23