Question

a 2 - cm - thick piece of cardboard placed over a radiation source would be most effective in protecting against which type of radiation?
alpha
beta
gamma
x - ray

an equation is shown below.
$_{1}^{2}h+_{1}^{2}h\to_{2}^{4}he$
which kind of reaction does the equation represent?
alpha decay
beta decay
nuclear fission
nuclear fusion

Explanation:

For the first question:

• Alpha radiation has the least penetrating power. A thin layer like cardboard can stop alpha particles. Beta radiation needs materials like aluminum, gamma and X - ray need dense materials like lead or concrete.

For the second question:

• Nuclear fusion is the process where two light nuclei combine to form a heavier nucleus. In the equation \(_{1}^{2}H+_{1}^{2}H

ightarrow_{2}^{4}He\), two hydrogen - 2 nuclei combine to form a helium - 4 nucleus. Alpha decay is the emission of an alpha particle (\(_{2}^{4}He\) nucleus) from a heavy nucleus. Beta decay involves the emission of a beta particle (electron or positron). Nuclear fission is the splitting of a heavy nucleus into lighter nuclei.

Answer:

1. Alpha
2. Nuclear fusion