Atomic Theory & Structure

In Bohr's model of the atom, where are the electrons located?

• in the center of the atom

• in energy levels outside the nucleus

• spread throughout the atom, like a chocolate chip cookie

Why is an atom considered electrically neutral?

• The number of protons equals the atomic number.

• The number of electrons equals the number of neutrons.

• The number of protons is the same as the number of electrons.

• The number of electrons equals the number of protons.

A subatomic particle with a neutral charge is called

• a proton

• an isotope

• an electron

• a neutron

__________ determine the chemical reactivity of an atom.

• Protons

• Electrons

• Isotopes

• Neutrons

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

An atom with the same atomic number but a different mass number is called

• an ion

• an isotope

• an element

__________ are used to identify the element.

• Electrons

• Periodic Table

• Protons

• Neutrons

If you change the number of neutrons, you change the __________.

• charge

• mass

• identity

How many protons are in Carbon-14?

• 6

• 8

• 14

• 12

How many neutrons are in Lithium-7?

• 4

• 3

• 7

• 5

Tags

NGSS.MS-PS1-1

An isotope contains 19 protons and 21 neutrons. What is it called?

• Potassium-21

• Potassium-40

• Calcium-20

• Calcium-40

Tags

NGSS.MS-PS1-1