Chemistry Chapter 3 test

The behavior of cathode rays in a glass tube containing gas at low pressure led scientists to conclude that rays are composed of

negative particles

The basic principles of atomic theory were first conceived by

Dalton

the las of multiple proportions is demonstrated by the compunds

CO and CO2

neutral atoms of the same element can differ in

mass number

Dalton's atomic theory helped to explain the law of conversation of mass because it stated that atoms

cannot be created or destroyed

millikan's experiments led to the determination

of approximate value of electron's mass

the discovery of the nucleus was a result of Rutherford's observation that a small percentage of the positively charged particles bombarding

we're deflected back toward the source

most of the volume of an atom is occupied by the

electrons

definite proportions

if a particular compound is composed of elements A and B, the ratio of the mass of B to the mass of A will always be the same.

Mole

the amount of a substance that contains a number of particles equal to the number of atoms in exactly 12g of carbon-12

electrons

any metal cathode used in a cathode-ray tube produces the same charged particles, all atoms included...............

the smallest particle of an element that retains the chemical properties of that element

atom

atoms of one element that have different masses are called

isotopes

the total number of protons and neutrons in the nucleus of an isotopes is called

mass

they short range attractive forces that hold the nuclear particles together are

nuclear forces