Biochemistry

The three particles that make up atoms are.

• protons, neutrons, isotopes

• neutrons, isotopes, and electrons

• positives, negatives, and electrons

• protons, neutrons, and electrons

The space surrounding the nucleus of an atom contains.

• protons

• electrons

• neutrons

• ions

The nucleus is made up of

• protons and electrons

• electrons and neutrons

• protons and neutrons

• protons, neutrons, and electrons

If a chlorine atom had 17 protons and 18 neutrons, it would be called

• chlorine-17

• chlorine-18

• chlorine-35

• chlorine-1

Isotopes are atoms of the same element with the same number of protons and

• a different number of electrons

• a different number of molecules

• a different number of neutrons

• the same number neutrons

Which of the following is a use of radioactive isotopes?

• can determine the age of rocks and fossils

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

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

• all of the above

if an atoms contains 11 protons and 12 neutrons, its atomic number is

• 1

• 11

• 12

• 23

Which of the following terms describes a substance formed by the combination of two or more elements in definite proportions?

• compound

• isotope

• nucleus

• enzyme

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

Which of the following is not true about chlorine?

• it is a poisonous, greenish gas

• It combines with sodium to form table salt.

• It was used to kill many soldiers in World War 1.

• It is not reactive.