_______ plays an important role in chemical reactions. When you _______ this you will have more collisions, particles moving faster and higher energy.
Question 4
4.
You have the same amounts of substances, one is granular and the other in powder. When they undergo a chemical reaction the powder reacts faster because it has more _______.
Question 5
5.
Question 6
6.
Question 7
7.
Question 8
8.
__________ are represented by equations.
Question 9
9.
Question 10
10.
Question 11
11.
Question 12
12.
Substances that are changed into something new are what?
reactants
chemical change
physical change
products
Chemical reactions that require constant energy are what type?
decomposition
synthesis
endothermic
exothermic
When you mix a crystal and water together the temperature goes down. This is a ____________ reaction.
exothermic
catalyst
inhibitor
endothermic
While mixing 2 liquid solutions you notice white particles at the bottom of the beaker. You know a chemical reaction took place because of the ______________.
solid
precipitate
color change
gas production
What is actually happening in a chemical reaction?
Chemical bonds are breaking and new bonds are forming because the electrons are moving.
Products are being formed.
Reactants disappear.
Reactants are becoming products and a new substance is formed.
While hiking in the woods, you see a brown rotting apple lying on the ground. What changes in the physical properties of the apple are sign that a chemical reaction has occurred?
brown color
piece missing
soft mushy feel
bright red color
After learning about chemical reactions, Olivia investigated different kinds of chemical changes using substances she found in her kitchen so she could see these changes. Which of the following can occur when a chemical reaction takes place? Choose all that apply.
New bonds form.
Changes don't affect matter.
Particles are smaller.
Existing bonds break.
Particles are larger.
New substances form.
Identify each item as either chemical change or physical change.
Water to ice
color change
energy change
size change
precipitation
precipitate
Physical Change
Chemical change
If something slows down a chemical reaction it is a(n) ______________.