11.1 Chemical changes

Question 1

What are the 2 groups chemical changes can be classified into?

Answer 1

1.) 2/more substances combine to form 1/more new substances
2.) substance breaks down into 2/ more new substances

Question 2

Physical changes

Chemical changes

Answer 2

-X new substances are formed
-changes can be reversed.

-1/more new substances are formed
-changes are not easily reversed.

Question 3

draw carbon dioxide as a word equation

H4 + O2 =

Answer 3

C + O2 = CO2

Question 4

the number of atoms in reactants and products are equal-T/F

Answer 4

T the number of atoms in reactants and products are equal

Question 5

What are the different type of chemical changes?

Answer 5

-Combustion
-Oxidation
-Thermal decomposition

Question 6

What is combustion?

Answer 6

-chemical reaction in which a substance is heated in the presence of O2 to form 1/more new substances

-heat/light is usually given out during combustion

Question 7

What is thermal decomposition

Answer 7

-chemical reaction in which a substance breaks down into 2/more simpler substances upon heating

Question 8

What is oxidation?

Answer 8

-Substance gains O2 and undergoes a chemical change called oxidation

-EG; rusting-iron + O2
-EG; cellular respiration-glucose = O2