Atoms STAAR Test

What is the mass number of a potassium (K) atom that has 20 neutrons? Hint: Use APEMAN

• 18

• 19

• 20

• 39

What is the charge of a proton?

• positive

• negative

• neutral

Which of the following best describes an electron?

• It has no charge and about the same mass as a proton

• It has a negative charge and much less mass than a proton

• It has a positive charge and much more mass than a neutron

• It has a negative charge and about the same mass as a neutron

Tags

NGSS.MS-PS2-3

Which subatomic particles are found in the nucleus?

• protons and neutrons

• protons and electrons

• neutrons and electrons

• just protons

Which subatomic particle is labeled with the number 3?

• proton

• neutron

• electron

Tags

NGSS.MS-PS1-1

Why do atoms react?

• To gain or lose electrons

• fill the outer shell

• to become stable

• All of these are true

Tags

NGSS.MS-PS1-5

All atoms of an element will ALWAYS have the same number of

• electrons

• protons

• neutrons

• none... they all can change

identity of an atom comes from:

• electrons

• neutrons

• protons

• valence electrons

Reactivity

of an atom comes from

• Electrons

• neutrons

• Protons

• Valence Electrons

The charge of a neutron

• Negative

• positive

• neutral

• magnetic