Chemistry Review

In the chemical formula 2H₂+ O₂-->2H₂O. What are the reactants?

• H, O

• 2H₂

• 2H₂+ O₂

• 2H₂O

In the chemical formula 2H₂+ O₂-->2H₂O. What is the product?

• 2H₂+ O₂

• 2H₂O

• O₂

• 2H₂

The ability to dissolve water and to conduct electricity are examples of

• physical properties
• chemical changes
• chemical properties
• chemical bonding

Which of the following is a physical property of an element?

• Color
• Ability to rust
• Flammability 
• Ability to tarnish

A chemical bond is

• A group of atoms that are joined together.
• The basic particle of matter.
• The force that holds two atoms together.
• A substance formed from the chemical combination of two or more atoms

Which of the following is an example of a chemical change?

• melting butter
• mixing milk and chocolate soup
• breaking glass
• burning gasoline

Which of the following is NOT true of atoms?

• They are composed of molecules.
• They can combine with other atoms.
• They make up elements.
• They are extremely small

The ability to change state and a substance’s size are examples of

• Physical properties
• Chemical changes
• Chemical properties
• Chemical bonding

Water is an example of

• an element
• A homogeneous mixture
• A compound
• A heterogeneous mixture

New substances are always formed when matter undergoes a

• Change in shape
• Physical change
• Change in temperature
• Chemical change