Question

20. Which statement is false? Rewrite it so that it is true. a. Fusion involves the combination of two smaller atoms into a larger atom. b. Fission involves the splitting of an atom into smaller atoms. c. Fission and fusion are two processes that release very little amounts of energy.

Answer 1

Answer:

c. Fission and fusion are two processes that release very little amounts of energy.

Explanation:

This statement is false. In fact, both fission and fusion are processes which release very large amounts of energy. The statement can be rewritten as it is true as follows:

"Fission and fusion are two processes that release very large amounts of energy."

Fission occurs when a large nucleus break apart, splitting into smaller nuclei, while fusion occurs when two light nuclei combine together into a larger nucleus. In both cases, the mass of the reactants is larger than the mass of the final products, so some of the mass has been converted into energy, according to Einstein's equation:

$E = \Delta m c^2$

where

E is the energy released

$\Delta m$ is the mass lost in the process

c is the speed of light

Since c is a very large number ($c=3\cdot 10^8 m/s$), we see that even a very small mass $\Delta m$ causes the released of a huge amount of energy, so both fission and fusion release large amounts of energy.