C, they could work together to make things from the top down.
1. Pure substances cannot be separated into any other kinds of matter, while a mixture is a combination of two or more pure substances.
2. A pure substance has constant physical and chemical properties, while mixtures have varying physical and chemical properties (i.e., boiling point and melting point).
3. A pure substance is pure, while a mixture is impure.
Answer:
Explanation: in exothermic reaction heat is released out
In endothermic reaction heat is absorbed
A.) Average acceleration = change in velocity/time = final velocity - initial velocity/time = 10-0/4 = 10/4 = 2.5m/s^2.
