Exploring Chemistry Concepts

What is the atomic number of carbon?

• 12

• 7

• 6

• 5

Which element has the symbol 'Na'?

• Potassium

• Calcium

• Sodium

• Magnesium

What is the smallest unit of an element?

• ion

• molecule

• compound

• atom

How many protons are in a neutral atom of oxygen?

• 6

• 12

• 10

• 8

What is the main characteristic of noble gases?

• They are highly reactive and form compounds easily.

• They have incomplete valence shells and readily gain electrons.

• They are all gases at room temperature and have low boiling points.

• They are chemically inert due to having a full valence shell of electrons.

What does the periodic table organize elements by?

• Mass number

• Atomic number

• Element name

• Chemical symbol

What is the charge of a neutron?

• +1

• +2

• 0

• -1

Which subatomic particle determines the identity of an element?

• Photon

• Neutron

• Proton

• Electron

What is the maximum number of electrons in the first energy level?

• 2

• 1

• 4

• 8

What is the difference between an atom and a molecule?

• Molecules are always larger than atoms and contain only one type of atom.

• An atom is a group of molecules, while a molecule is a single element.

• An atom is a single unit of an element, while a molecule is a group of two or more atoms bonded together.

• Atoms can exist independently, but molecules cannot.