Counting Atoms and Molar Mass

The carbon-12 atom is assigned a relative mass of exactly

• 6 amu

• 1 amu

• 24 amu

• 12 amu

Carbon-14 (atomic number 6) has

• 6 neutrons

• 8 neutrons

• 14 neutrons

• 20 neutrons

Isotopes are atoms of the same element that have different

• numbers of electrons

• numbers of protons

• chemical properties

• masses

Tags

NGSS.HS-PS1-8

The number of atoms in 1 mole of carbon is

• 6.022 x 10²³

• 6.022 x 10²⁴

• 2.006 x 10²³

• 6.220 x 10²⁷

The total number of protons and neutrons in the nucleus of an atom is its

• mass number

• average atomic mass

• atomic number

• Avogadro number

Tags

NGSS.HS-PS1-8

Chlorine has atomic number 17 and mass number 35. It has

• 17 protons, 17 electrons. and 52 neutrons

• 17 protons, 17 electrons, and 18 neutrons

• 35 protons, 35 electrons, and 17 neutrons

• 18 protons, 18 electrons, and 17 neutrons

Tags

NGSS.MS-PS1-1

All atoms of the same element have the same

• atomic number

• mass number

• atomic mass

• number of neutrons

The average atomic mass of an element is the average of the atomic masses of its

• two most abundant isotopes

• radioactive isotopes

• artificial isotopes

• naturally occurring isotopes

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

• 27

• 40

• 14

• 13

Tags

NGSS.MS-PS1-1

The atomic mass of an element listed in the periodic table is the

• average atomic mass

• relative atomic mass of the most radioactive isotopes

• mass number of the least abundant isotope

• relative atomic mass of the most abundant isotope