A pure substance is something that occurs in nature. An element is made up of one type of atom only and cannot be split further.
In simpler terms it is true an element is a substance that is made of ONE type of atom
Answer:
d). they base their conclusions on models that make different assumptions.
Explanation:
Economist are persons who studies economics and the past historical trends and then make them to forecast the future trends. Basically an economists analyzes the issues including consumer demand or sales to help an organization maximize the profits.
When an economist is given two different government policies and is ask to choose between them, they tend to disagree because economist generally make their conclusions on the basis of their models which end up in having different assumptions.
Models help the economist to predict and explain the economic behavior in the real world.
Hence the answer is (d)