Chemical Reactions Vocabulary

A change in appearance without a change in chemical make-up.

A change in chemical make-up with a new substance formed.

A change that is hard to reverse.

A change in appearance without a change in chemical make-up.

A change in chemical make-up with a new substance formed.

A change that is easy to reverse.

CO₂ is made as a new product

Always a Chemical Change

Physical Change

Lighting a Match

Powdered sugar turning brown when cooked

A) The starting chemicals or molecules

B) The ending chemicals or molecules

C) The ones that go in

A) Mass is created in a chemical reaction

B) Mass is destroyed in a chemical reaction

C) Mass is neither created nor destroyed in a chemical reaction

stir in

melt

freeze

evaporate

A chemical or molecule you add to a chemical reaction to speed it up but it isn’t part of the reaction, the molecule itself doesn’t change. Example: water helps a bike rust so it is a catalyst, but it doesn’t take part in the reaction between iron and water.

A substance that slows down a chemical reaction without being consumed.

A molecule that is consumed in a chemical reaction to produce energy.

A reactant that is permanently altered in a chemical reaction.

A reaction that sucks up heat as it happens, it results in a colder product.

A reaction that releases heat, making the surroundings warmer.

A reaction that occurs spontaneously without any energy input.

A reaction that gives off heat as it happens, it results in a hotter product.

A reaction that absorbs heat and results in a cooler product.

A reaction that occurs only in the presence of light.