The given question is incomplete. The complete question is as follows.
Which of the following best helps explain why an increase in temperature increases the rate of a chemical reaction?
(a) at higher temperatures, high-energy collisions happen less frequently.
(b) at low temperatures, low-energy collisions happen more frequently.
(c) at higher temperatures, less-energy collisions happen less frequently.
(d) at higher temperatures, high-energy collisions happen more frequently
Explanation:
When we increase the temperature of a chemical reaction then molecules of the reactant species tend to gain kinetic energy. As a result, they come into motion which leads to more number of collisions within the molecules.
Therefore, chemical reaction will take less amount of time in order to reach its end point. This means that there will occur an increase in rate of reaction.
Thus, we can conclude that the statement at higher temperatures, high-energy collisions happen more frequently, best explains why an increase in temperature increases the rate of a chemical reaction.
Answer:
Answers in explanation.
Explanation:
30. A (A chemical changes changes the chemical properties)
31. C (rusting is an example of a chemical change
32. B (A reaction requires energy, so some energy will be expelled)
33. B (Color change is an example of a chemical change)
34. A (The law of the conservation of mass: Mass and Energy cannot be created nor destroyed)
Jeez this is middle school really. covalently bond
Answer : The correct option is A.
Explanation :
The given chemical reaction is,

In the reaction, Reactants are present on the left side of the arrow and products are present on the right side of the arrow.
Reactants are those which takes part in and undergoes change during the reaction.
Products are those which are formed during the reaction.
In the given reaction, zinc react with hydrochloric acid to form zinc chloride and hydrogen gas.
Therefore, the reactants are zinc and hydrochloric acid.
Answer:
545.2
Explanation:
To read a beam balance, you need to add together the numbers that each balance reads.
The first beam reads 500.
The second beam reads 40.
The third beam reads 5.2.
500 + 40 + 5.2 = 545.2
The total mass of the rock sample is 545.2.