Study guide for Chemical reactions and energy

Question 1

Kinetic Energy

Answer 1

• Kinetic energy is the energy something has because it is moving

Question 2

Potential energy

Answer 2

• Potential energy is energy stored in an object
• When you lift an object, you store EPE

Question 3

Chemical change

Answer 3

• is when the properties of a substance are different before something happens to it and after something happened to it (aka the object changes)

Question 4

Laboratory tools:

Answer 4

• Sometimes we use tools in the laboratory to help us make observations because it is safer.
• doing this, we get more accurate information than what our senses alone can provide

Question 5

Chemical Potential energy:

CHEMICAL

Answer 5

When energy is stored in chemical substances, it is called chemical potential energy

Question 6

Reactent vs product:

before and after

Answer 6

• Reactant is the first part of the equation (to the left of the arrow)
• Product is the second part of the equation (to the right of the arrow) The product is the result after a chemical reaction (the arrow)

Question 7

Endothermic vs exothermic:

End = cold war, both make their surrondings feel something

Answer 7

Endothermic: Endothermic reactions absorb energy from their surroundings. This makes the area around the reaction feel cooler.

Exothermic: Exothermic reactions release energy into its surroundings. This makes the area around the reaction feel warm or hot.

Question 8

Heat:

two objects

Answer 8

Heat is the energy that is transferred between two objects that are at different initial temperatures

Question 9

Temperature

Answer 9

warmer or colder

Question 10

Thermal energy:

all molecules

Answer 10

• The total KE + PE associated with ALL molecules in a substance ; Responsible for the object having a measurable temperature

Question 11

Physical change:

Answer 11

• is when a substance changes its properties without changing what substance is
• the key idea is that the formula does not change

Question 12

Conservation of matter:

has to do with atoms, remember reactent and product table

Answer 12

• The atoms can’t change type. If we start with 3 carbon atoms and 6 oxygen atoms, we must start with 3 carbon atoms and 6 oxygen atoms.

Question 13

Conservation of mass:

chemical reaction

Answer 13

When a chemical reaction happens, atoms are not allowed to be created or destroyed. If we start with 4.2g of a substance we must end with 4.2g of a substance.

Question 14

Chemical reaction:

the key idea is?

Answer 14

• is when a substance changes its properties by changing what substance is
• the key idea is that the formula changes

Question 15

Phase changes:

thermal energy, extra energy

Answer 15

Thermal energy also changes when a substance changes phase

• If you measure the temperature of ice cream when it melts or of water when it boils, the temperature stays constant until the phase change finishes
• Extra energy must be added to make those phase changes happen.