Chemistry of Life

The space surrounding the nucleus of an atom contains

• Protons

• Neutrons

• Ions

• Electrons

Which of the following is a use of radioactive isotopes?

• can determine the ages of rocks and fossils

• can be used to treat cancer and kill bacteria that cause food to spoil

• used as "tracers" to follow the movements of substances within organisms

• all of the above

Which of the following makes up a molecule of water?

• one atom of hydrogen and one atom of oxygen

• one atom of sodium and one atom of chlorine

• one atom of hydrogen and two atoms of oxygen

• two atoms of hydrogen and one atom of oxygen

Tags

NGSS.MS-PS1-1

Which of the following statements about a compound is true?

• The physical and chemical properties of a compound are usually very different from those of the elements from which it is formed.

• Only the physical properties of a compound are usually the same as those of the elements from which it is formed.

• Only the chemical properties of a compound are usually the same as those of the elements from which it is formed.

• The physical and chemical properties of a compound are usually the same as those of the elements from which it is formed.

Tags

NGSS.HS-PS1-1

What type of electron is available to form bonds?

• valence

• ionic

• nucleus

• covalent

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

What type of ion forms when an atom loses electrons?

• neutral

• negative

• positive

• possibly positive or negative

Ice floats on water because

• of cohesion.

• ice has a higher density than water.

• water shrinks when it freezes.

• water expands when it freezes.

The most abundant compound in most living things is

• carbon dioxide.

• sodium chloride.

• water.

• sugar.

When salt is dissolved in water, water is the

• reactant.

• solution.

• solute.

• solvent.

A substance with a pH of 6 is called

• an acid.

• a base.

• both an acid and a base.

• neither an acid nor a base.