Chemistry of Life Check-in

Choose the best definition of an element.

• A substance that contains two or more types of atoms chemically bonded together

• Pure substance consisting of a single atom.

• Contains protons, neutrons, and electrons and is the smallest unit of life.

• A mixture of atoms and molecules that can be separated physically

Select all that apply: Which of the following are parts of an atom?

• Mitochondrions

• Protons

• Electrons

• Neutrons

What type of bond requires the transfer of electrons?

• Covalent

• Metallic

• Hydrogen

• Ionic

Which type of bond involves the sharing of electrons?

• Ionic

• Covalent

• Metallic

• Hydrogen

What atoms are present in a water molecule (H2O)?

• 1 hydrogen, 2 oxygen

• 2 helium, 1 oxygen

• 2 hydrogen, 1 oxygen

• 1 helium, 2 oxygen

What causes a water molecule to be polar?

• Oxygen having a slight negative charge and hydrogen having a slight positive charge

• It has an equal number of protons and electrons

• It contains both positive and negative ions

• The hydrogen and oxygen atoms are equally charged