Atomic Structure

The atomic number identifies the number of __________.

• electrons

• atoms

• protons

• neutrons

Subatomic particles that have a negative charge

• electrons

• protons

• quarks

• neutrons

Subatomic particles with a positive charge

• neutrons
• atomic mass
• protons
• isotopes

These are found in the nucleus and have a neutral charge.

• proton

• electron

• neutron

Value representing the number of protons in an element

• Atomic Mass
• Mass Number
• Valence Electrons
• Atomic Number

An atom has 25 protons and 30 neutrons. How many electrons are needed to make the atom neutral?

• 0

• 25

• 30

• 35

Look at this picture of Argon off the periodic table. Which of the following is true for this element?

• 18 protons

• 40 protons

• 22 protons

• 21.9 protons

The atomic mass of an atom is equal to

• number of protons plus number of neutrons

• number of protons plus number of electrons

• number of electrons plus the number of neutrons

The nucleus of an atom is made of

• electrons and protons
• electrons and neutrons
• protons and neutrons
• empty space

Outside the nucleus of an atom are these

• protons
• neutrons
• quarks
• electrons