Chemical Reactions Vocabulary

What is a physical change?

• 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.

What is a chemical change?

• 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.

Match correctly

• Powdered sugar turning brown when cooked

• Adding or taking away energy

• CO₂ is made as a new product

• Color change

• Always a Chemical Change

• Particles Spread out but stay the same chemical

• LIghting a Match

• Bubbles appear

• Physical Change

• New substance with a new chemical formula is made

What are reactants in a chemical equation?

a

b

c

Reactants

Products

Photosynthesis

What are products in a chemical equation?

• A) The starting chemicals or molecules

• B) The ending chemicals or molecules

• C) The ones that go in

What is the conservation of mass?

• 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

Dissolve is a physical change that means to ______.

• stir in

• melt

• freeze

• evaporate

What is a catalyst?

• 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.

What is an endothermic reaction?

• A reaction that sucks up heat as it happens, it results in a colder product. For example when you mix the chemicals in an ice pack, the result is the packet gets colder.

• A reaction that releases heat, making the surroundings warmer.

• A reaction that involves the absorption of light energy.

• A reaction that occurs spontaneously without any energy input.

What is an exothermic reaction?

• A reaction that gives off heat as it happens, it results in a hotter product. For example when you mix two chemicals together in a hand warmer, the result is the packet gets hot.

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

• A reaction that involves the exchange of electrons between two substances.

• A reaction that occurs only in the presence of light.