The coins in 1991 had more copper in them compared to the coins today. So, that is why it worth 3.3p.
The question asks about the average kinetic energy so it is not related with mass. We only need to compare the temperature. The higher temperature is, the higher kinetic energy is. So the answer is (2).
Answer:B) a reactant that undergoes reduction
Explanation:
Oxidation reaction is defined as the reaction in which a substance looses electrons. The oxidation state of the substance increases during oxidation.
Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation state of the substance gets reduced during reduction.

Overall reaction: 
The substance M which itself gets oxidized, reduces other and is called as reducing agent. The substance N which itself gets reduced, oxidizes other and is called as oxidizing agent.
Answer:
The state with the lowest possible energy consistent with the state of maximum disorder
so letter A
Answer:
Like stratovolcanoes, they can produce violent, explosive eruptions, but their lava generally does not flow far from the originating vent. Cryptodomes The 1980 eruption of Mount St. Helens was an example; lava beneath the surface of the mountain created an upward bulge which slid down the north side of the mountain.
Explanation: