Answer:
chemical changes
Explanation:
A chemical change is one in which a new kind of matter is formed. It is always accompanied by energy changes. The process is not easily reversible and hence, it is a permanent procedure.
Burning of charcoal produces a new kind of produces in the combustion process.
Both heating of copper(ii)carbonate strongly and zinc oxide will lead to a decomposition reaction in which new compounds are formed.
When organisms and plants died and sank to the bottom of swamps and oceans, brown soil-like materials called peat are formed. Over millions of years, the peat became covered with sand, clay and other minerals and the peat is converted into layers of sedimentary rocks. After a long time, different type of fossil fuels are formed.
<span>The first method to determine the chemical composition of a substance in space was using light. By determining red shift in the observed spectrum of light they could determine the elements they were observing. Different elements change the way light behaves and from this scientists can determine the makeup of things such as stars and nebulas.</span>
Answer:
His results will be skewed because there was more water than stock solution. Which would cause the percentage solution to be less than 50% therefore the density would be less than the actual value.
Explanation:
The solution will have percentage less than that of 50%. Therefore the density would be less than the actual value.
Suppose there should be 50 mL of the solution, and he added 60 mL. So 10 mL of the solution is added more.
Suppose the mass of the solute is m.
Originally, the density is = 
Now after adding extra 10 mL , the density becomes 
.
Therefore, 
So the density decreases when we add more solution.
