Understanding Basic Chemistry Concepts

What does chemistry help us understand?

• How things look, feel, and behave

• The biggest and tiniest things in the universe

• Everything that cannot be seen with the naked eye

• All of the above

What is stoichiometry used for?

• Measuring the temperature of chemicals

• Measuring chemicals that go into and come out of a reaction

• Creating new chemical elements

• Observing chemical reactions without measurement

How is an Atomic Mass Unit (AMU) defined?

• As the mass of a single hydrogen atom

• As 1/12 the mass of an atom of Carbon-12

• As the average mass of all naturally occurring elements

• As 1/16 the mass of an atom of Oxygen

What is the name for the number of atoms in 12 grams of Carbon-12?

• Planck's constant

• Avogadro's Number

• The atomic number

• The mass number

How many atoms are in one mole of any element?

• 6.022 x 10^23

• 12

• 16

• 1.008

What is the molar mass of an element?

• The number of atoms in one mole of the element.

• The mass of one atom of the element.

• The relative atomic mass of the element in grams.

• The total number of protons and neutrons in an atom.

What happens to the number of atoms of each element during a chemical reaction?

• The number of atoms changes, but the mass stays the same.

• The number of atoms of each element stays the same.

• New atoms are created, and old atoms are destroyed.

• Atoms are rearranged, and their total number decreases.

Why is it important to balance a chemical equation?

• To make the equation look neater.

• To show how much of each substance is going in and coming out of a reaction.

• To make sure the equation is easy to read.

• To change the types of atoms involved in the reaction.