Chemical Reactions Key Terms Part 1

A water molecule is made of hydrogen and oxygen atoms. Based on the key terms, what is H2O an example of?

• A model

• A molecule

• A coefficient

• A property

What does boiling point describe?

• The temperature when a solid changes into a liquid

• The small number after an element in a formula

• The temperature when a liquid changes into a gas

• The number of molecules shown in front of a formula

Water boils and turns to steam at 100°C. This sentence illustrates which key term?

• Melting point

• Boiling point

• Corrosive

• Product

According to the definition, what is a chemical formula?

• A picture that helps explain something

• Letters and numbers that show which atoms are in a substance

• A characteristic that can be observed or measured

• A process where atoms rearrange to form new substances

In the example with vinegar and baking soda making carbon dioxide gas, the carbon dioxide is best classified as the:

• Coefficient

• Model

• Product

• Property

What does a coefficient indicate in a chemical equation?

• How many atoms are in one molecule

• How many molecules are present

• The temperature when a liquid becomes a gas

• A large repeating crystal pattern

What does a subscript show in a chemical formula?

• The number of molecules

• The temperature of a phase change

• How many atoms are in one molecule

• That the substance is corrosive

In H2O, what does the 2 indicate?

• Two hydrogen atoms in one molecule

• Two water molecules

• Two oxygen atoms in one molecule

• Two different elements chemically combined

Which statement best defines a molecule as used in the key terms?

• Two or more different elements chemically combined

• Two or more atoms bonded together

• A picture or computer design used to explain something

• A new substance made in a chemical reaction

Which definition correctly describes a compound?

• Two or more atoms bonded together

• Two or more different elements chemically combined

• A characteristic that can be observed or measured

• Able to cause damage by wearing away materials