Answer:
2 significant figures i.e. 2 and 7.
Explanation:
We need to find the number of significant figures in the given number i.e. 
.
It has 2 significant figures i.e. 2 and 7.
It means the power of 10 doesn't count in the significant figures.
Hence, there are 2 significant figures.
Answer:
The principle of uniformitarianism describes the fact that the geological processes used to occur in the past were in the same manner and with the same intensity that as they occur in the present on the planet Earth. Therefore, uniformity in the geological processes exhibit from the unknown and unobservable past to present scenario of Earth. The present is the key to the past is the slogan of the principle of uniformitarianism.
Answer:
True
Explanation:
The complete question is:
<u><em>"A reaction contains two reactants, A and B. If A is doubled, there will be a greater number of effective collisions between reactants. TRUE FALSE"</em></u>
Collision Theory indicates that chemical reactions take place because molecules, atoms or ions collide with each other.
Furthermore, the molecules must collide effectively, that is, not all reagent collisions lead to product formation. Effective shock means that the reagent molecules have enough kinetic energy at the time of the shock for their bonds to break and product bonds to form. In addition, the molecules of the reagents must be properly oriented for the reaction to take place.
As the concentration increases, the number of shocks increases. In other words, by increasing the concentration of the reactants, the probability of collision between their molecules increases, and therefore the number of effective collisions.So the statement is true-
