Ch 3 Review Flashcards
The subatomic particle with a negative charge.
electrons
The electrons were first discovered while studying a ________
cathode ray
The number s of atoms or particles in one mole of a substance.
Avogadros number
The subatomic particle found in the nucleus with no charge.
neutrons
The number of protons in an atom is equal to the ______
atomic number
The mass in grams of 1 mole of a substance.
molar mass
the particles that make up an atom are called
subatomic particles
the small dense center of an atom that contains most of the atom’s mass, but very little of the atom’s volume
atomic number
the unit used when talking about the mass of an atom
nucleus
the model of the atom suggested by JJ Thompson that consists of a positive mass with negative charges
plum pudding model
the law of _____ states that in a chemical reaction, mass cannot be created or destroyed. this means the mass of the products is equal to the mass of the reactants
conservation of mass
the charge of an electron
negative
the law of ____ states that if two or more compounds are made up of the same two elements the ratio of the masses of the second element is always a ratio of small whole numbers
multiple proportions
a region in an atom where there is a high probability of finding an electron.
orbital
dalton’s ___ consist of 5 parts talking baout properties of atoms
atomic theory
the law of ____ states that a chemical compound always contains the same elements in exactly the same proportions by weight or mass
definite proportions
the number of protons and neutrons
mass number
the mass of an atom expressed in atomic mass units
atomic mass
the scientist credited with the discovering the nucleus of an atom with his gold foil experiment
rutherford
the man who is credied with discovering the electrons
JJ thompson
the difference in energy between two wnergy levels
quantum
when an electron is in the lowest energy level possible, it is in a
ground state
the force that holds the nucleus of an atom together
strong force
the subatomic particle found in the nucleus with a positive charge
proton
the arrangement of electrons in an atom
electron configuration
the SI unit used to measure the amount of a substance. it is equal to 6.022*10^23
mole
atoms of the same element with different numbers of neutrons
isotopes
the atomic mass unit is defined as one-twelfth of the mass of one ___ atom
carbon-12
when an electron gains energy and moves to a higher energy level, it is in an __
excited state
rutherford concluded the atom is mostly ____ space
empty
the charge on a proton
positive
___model of the atom has electrons orbiting the nucleus at certain distances corresponding to certain amounts of energy
bohr model
