Atomic Structure

What is the smallest unit of matter? It is composed of protons and neutrons, held together in the nucleus, and electrons around the nucleus in different electron orbitals, which form an electron cloud.

• cell

• nucleus

• atom

• electron

What is a subatomic particle with a positive charge that is in the nucleus of an atom?

• neutron

• proton

• electron

• valence electron

What is a subatomic particle with a negative charge? It is found in the electron cloud surrounding the nucleus.

• neutron

• proton

• electron

• electron cloud

What is the center of an atom containing protons and neutrons?

• nucleus

• neutron

• proton

• electron cloud

What is atomic number?

• Number of protons in an atoms 
• Number of neutrons in an atom
• Mass of an atom
• Charge on an atom

Which subatomic particles are found in the nucleus of an atom?

• Protons and Electrons
• Protons and Neutrons
• Neutrons and Electrons
• Protons, Neutrons and Electrons

The total number of protons and neutrons in an atom is called the...

• Atomic number
• Proton number
• Mass number
• Weight number

Complete the missing label on the diagram.

• Neutron
• Centre
• Nucleus
• Sub atomic particle

The _________ of an element equals the number of protons in an atom of that element.

• mass number

• atomic weight

• atomic number

• isotopes

The __________ of an atom is the sum of the protons and neutrons in the nucleus of that atom.

• mass number
• atomic number 
• atomic weuight
• isotope weight