Chapter 3 Chemistry Test
law of definite proportions
A chemical compound always has the same elements in the same proportions by mass regardless of the source of the compound. This is a statement of_______.
the atom is mostly empty space
An important result of Rutherford's experiments with gold foil was to establish that__________.
subdivided, created, or destroyed
Atoms cannot be ______,_______, and ______.
protons and neutrons
Except for the nucleus of the simplest type of hydrogen atom, all atomic nuclei are made of ______ and _______.
electron
Has the least amount of mass
2.33mol
How many moles of carbon are in a 28.0g sample?
69
How many neutrons are present in an atom of tin that has atomic number of 50 and a mass number of 19?
Law of Multiple Proportions
If 2 or more different compounds are composed of the same 2 element, then the ratio of the masses of the 2nd element combined with a certain ratio of small whole numbers.
Law of Conservation
Matter cannot be created or destroyed in ordinary chemical reactions.
6.17g
What is the mass of 1.20x10(23) atoms of phosphorus.
34.5g
What is the mass of 1.50 mol of sodium, Na?
Isotopes
atoms of the same element that have different masses
Rutherford
he gave more detail of the atom's structure
Millikan
he measured the charge of an electron
Thomson
he was given credit for the discovery of the electron
mole
the amount of a substance that contains as many particles as there are atoms in exactly 12g of carbon -12
3
the mass of a proton and neutron is _____.
0
the mass of an electron is ____.
molar mass
the mass of on mole of a substance (g/mol)
Avogadro's Number
the number of particles in exactly one mole of a pure substance.
atomic number
the number of protons of each atom of an element
relative atomic mass
the weighted average of an element as compared to the standard atom
average atomic mass
the weighted average of the atomic masses of the naturally occurring isotopes in an element
strong
when two protons are extremely close to each other, there is a ____ attraction between them.
electrons
Cathode rays are composed of ______.
negatively charged particles
Cathode rays were composed of ______.
protons
The atomic number of an element is the same as the number of _____.
proton
The subatomic particle that has a charge of +1
chemical reaction
The transformation of a substance or substances into one or more new substances is known as a ______.
neutron
a neutral particle in the nucleus
electron
a particle that is negatively charged and surrounds the nucleus
proton
a positively charged particle
nucleus
a very small region located in the center of an atom
atoms
extremely small particle of an element that retains the chemical properties of that element
