Answer: a. 0.8 tons p. month.
Explanation:
Given: Total nuclear waste = 60,000 metric tons
Time take = 60 years = 12 x 60 months [ 1 year = 12 months]
= 720 months
Total nuclear power plants = 104
Now , Average waste produced by each plant = 
Hence, 0.8 tons p. month is produced by each plant.
So, option a. is correct.
Liquids have free and fast moving particles. Liquids do not take a specific shape unless they are enclosed such as in a bottle. Anyway, since they are free flowing when they freeze, their movement becomes very slow. Eventually the particles will not have room to move as they used to and will be held in one place. The particles are still moving but they are only shaking or vibrating in the same place. You can't even tell this movement is happening, and that is what happens when liquid freezes.
Explanation:
atom changes from a ground state to an excited state by taking on energy from its surroundings in a process called absorption. The electron absorbs the energy and jumps to a higher energy level. In the reverse process, emission, the electron returns to the ground state by releasing the extra energy it absorbed
