Atoms of elements in the same group of the periodic table share the same

• number of energy levels

• number of valence electrons

• atomic numbers

• atomic masses

The atomic mass number of magnesium is 24. Therefore its nucleus must contain

• 12 protons and 12 neutrons

• 6 protons and 6 electrons

• 12 neutrons and no protons

• 12 protons and no electrons

Tags

NGSS.MS-PS1-1

A neutral atom may contain 8 protons, A. 9 neutrons and 10 electrons B. 8 neutrons and 10 electrons C. 9 neutrons and 8 electrons D. 10 neutrons and 9 electrons

• 9 neutrons and 10 electrons

• 8 neutrons and 10 electrons

• 9 neutrons and 8 electrons

• 10 neutrons and 9 electrons

Tags

NGSS.MS-PS1-1

An element with 5 protons, 6 neutrons, and 8 electrons has an atomic number of A. 5 B. 6 C. 8 D. 11

• 5

• 6

• 8

• 11

An element with 5 protons, 6 neutrons, and 8 electrons has a mass number of A.

• 5

• 6

• 8

• 11

The farther an electron is from the nucleus, the more (a)   it has.

• charge

• energy

• mass

• pull

The majority of the mass of the atom is located in the (a)   and the majority of the volume of the atom is located in the (b)   .

• Nucleus, electron cloud

• Nucleus, nucleus

• Electron cloud, nucleus

• Electron cloud, electron cloud

Atoms of the same element that have different numbers of neutrons are called

• molecules

• ions

• protons

• isotopes

The total number of electrons in the outer shell of a sodium atom is

• A. 1

• B. 2

• C. 8

• D. 18

Which particles determine the atomic number of an element?

• Protons only

• Neutrons only

• Neutrons and protons

• Protons and electrons