Atoms and Atomic Theory

In a neutral atom, the numbers of protons and electrons are _____.

• not the same

• the same

The charge on an atom is _____.

• positive

• negative

• neutral

• none of these

Tags

NGSS.MS-PS2-3

A neutral atom has 40 electrons and 46 neutrons. How many protons does it have?

• 40

• 46

• 86

• 80

A neutral atom has 22 electrons and 24 neutrons.  What is its atomic number?

• 24

• 22

• 20

• 45

The atom's mass is found mostly in the atom's  _____.

• nucleus

• protons

• electrons

• electron cloud

What is the atomic number of an atom that has 12 protons, 13 neutrons, and 12 electrons?

• 2

• 13

• 25

• 12

Tags

NGSS.MS-PS1-1

Two isotopes of the same element have the same number of  _____.

• electrons

• atoms

• neutrons

• protons

The atomic number of an element tells us the number of protons and neutrons in a specific isotope.

• True

• False

The atomic number is the number of protons in the nucleus and it also identifies the element.

• true

• false

What makes isotopes of the same element different from each other?

• The number of protons in their nucleus

• The number of neutrons in their nucleus

• The number of electrons they have

• The number of protons + neutrons in the nucleus