Chemical Reactions and Evidence Quiz

What is a chemical reaction?

• A process where substances change into new substances

• A process where substances just mix but stay the same

• A physical change like melting or freezing

• A scientist mixing anything in a lab

What is evidence of a chemical reaction?

• Gas bubbles, temperature change, or new color

• Mixing powders that don’t change

• Stirring faster to make something dissolve

• Adding more water to dilute a solution

What is gas formation evidence?

• Bubbles forming during a reaction

• Pouring soda into a cup

• A solid dissolving in water

• Ice melting into liquid

What is color change evidence?

• A new color appears during a reaction

• Mixing paint colors together

• A shadow changing with the light

• Water turning clear when stirred

What is temperature change evidence?

• The reaction releases or absorbs heat

• A thermometer left in the sun gets hotter

• Cold water warms up in a room

• Ice melts because the room is warm

What is light formation evidence?

• A glow or flash of light produced during a reaction

• Turning on a flashlight

• The sun rising in the morning

• A light bulb being plugged in

What is a precipitate as evidence?

• A solid that forms from a liquid solution in a reaction

• A solid that was already there before mixing

• Any powder dissolved in water

• A liquid that evaporates into gas

What is a physical change?

• A change in state or form without making a new substance

• A change that always creates new substances

• A reaction with heat and bubbles

• A scientist mixing chemicals to test them

What is a mixture?

• Two or more substances combined without a chemical reaction

• A new substance formed by combining elements

• A chemical compound

• A reaction that produces gas

What is a new substance?

• A product created in a chemical reaction with different properties

• The same substance in a different form

• Ice melting into water

• Powder dissolving in water