Independent: Gasoline with different amounts of lead
Dependent: Amount of pollution produced
Answer:

Explanation:
= Mass of metal = 19 g
= Specific heat of the metal
= Temperature difference of the metal = 
V = Volume of water = 150 mL = 
= Density of water = 
= Specific heat of the water = 4.186 J/g°C
= Temperature difference of the water = 
Mass of water

Heat lost will be equal to the heat gained so we get

The specific heat of the metal is
.
Explanation:
Method of prepration of sodium thiosulphate - definition
In the laboratory, this salt can be prepared by heating an aqueous solution of sodium sulphite with sulphur or by boiling aqueous NaOH and sulfur according to this equation:

Answer:
The bottom is troposhere the next is sratoshere,mesosphere,thermosphere then exoshere
Explanation:
A. DNA is copied.
- The cell duplicates its DNA in order to have a complete set in eac cell when it divides.