Apologia Physical Science

The number of ____ in an atom is the atomic number.

• electrons

• protons

• neutrons

A region of space around the nucleus where electrons are most likely to be found.

• Rings

• Orbitals

• Pipe cleaners

Where is almost all of the mass of an atom found?

• protons

• neutrons

• electrons

• nucleus

What type of particle is an electron?

• a negative charge, found in the nucleus

• a negative charge, found outside the nucleus

• a positive charge, found outside the nucleus

• no charge, found outside the nucleus

Tags

NGSS.MS-PS2-3

The atomic number of argon is 18. How many electrons are there in argon-38?

• 16

• 18

• 20

• 56

How many neutrons would be in argon-38?

• 16

• 18

• 20

• 56

If elements have the same number of valence electrons, they are

• called halogens

• called noble gases

• in the same group

• in the same period

Which elements are all gases?

• Group 1A

• Group 2A

• Group 7A

• Group 8A

Which statement about oxygen-17 and oxygen-18 is true?

• They have identical mass.

• They are isotopes of oxygen.

• They have different numbers of protons.

• They have different numbers of electrons.

What is the maximum number of electrons that an atomic orbital can contain?

• 2

• 4

• 8

• 16