The law of conservation of mass follows from the concept that

The composition of the two oxides of lead, PbO and PbO2, are explained by the

Who first proposed an atomic theory based on scientific knowledge?

According to Dalton’s atomic theory, atoms

Which of the following is NOT part of Dalton’s atomic theory?

The law of definite proportions

In a cathode tube, electrical current passes from one electrode, the _____, to the

Experiments with cathode rays led to the discovery of the

Who explained the behavior of positively charged particles being deflected from a metal foil as the nucleus?

In the gold foil experiment, most of the particles fired at the foil

The gold foil experiment led to the discovery of the

What did Rutherford conclude about the structure of the atom?

A nuclear particle that has about the same mass as a proton, but with no electrical charge, is called a(n)

Which part of an atom has a mass approximately equal to 1/2000 of the mass of a common hydrogen atom?

The mass of a neutron is

The nucleus of most atoms is composed of

Protons and neutrons strongly attract when they

An aluminum isotope consists of 13 protons, 13 electrons, and 14 neutrons. Its mass number is

Isotopes are atoms of the same element that have different

Atoms of the same element that have different masses are called

Isotopes of an element contain different numbers of

When the light from excited atoms of an element is passed through a prism, the distinct colored lines produced are called

Bohr’s theory helped explain why

According to Bohr’s theory, an excited atom would

If electrons in an atom have the lowest possible energies, the electrons are in their

For an electron in an atom to change from the ground state to an excited state,

Most of the volume of an atom is occupied by the

The main energy levels of an atom are indicated by the

The statement that an electron occupies the lowest available energy orbital is

“Orbitals of equal energy are each occupied by one electron before any is occupied by a second electron, and all electrons in singly occupied orbitals must have the same spin” is a statement of

The statement that no more than two electrons in the same atom can occupy a single orbital is

Which of the following rules requires that each of the p orbitals at a particular energy level receive one electron before any of them can have two electrons?

Two electrons in the 1s orbital must have different spin quantum numbers to satisfy

The sequence in which energy sublevels are filled is specified by

Which is the ground-state electron configuration for ?