Atomic Structure

Front

Hydrogen has three isotopes with mass numbers of 1, 2, and 3 and has an average atomic mass of 1.00794 amu. What does this indicate?

Back

More isotopes have an atomic mass of 1 than of 2 or 3.

Front

Which electron shell in an atom of calcium in the ground state has an electron with the greatest amount of energy?

Back

4

Front

An orbital is a region in an atom where there is a high probability of finding

Back

an electron

Front

In all atoms of bismuth, the number of electrons must equal the:

• number of protons
• number of neutrons
• sum of the number of neutrons and protons
• difference between the number of neutrons and protons

Back

number of protons

Front

Which statement describes the earliest model of the atom?

Back

An atom is an indivisible hard sphere

Front

Atoms are neutral because the number of

Back

protons equals the number of electrons

Front

An ion that consists of 7 protons, 9 neutrons, and 10 electrons has a net charge of

Back

-3

Front

Order the atomic model descriptions from earliest to most recent:

A: electron shells outside a central nucleus

B: hard, indivisible sphere

C: mostly empty space

Back

B, C, A

Front

Which particle has the least mass? Options: a proton, an electron, a helium atom, a hydrogen atom

Back

an electron

Front

Which phrase describes the charge and mass of a neutron?

Back

no charge and an approximate mass of 1 u