Physics 9702 · AS & A Level · Atoms, nuclei and radiation

Atoms, nuclei and radiation — practice question

An electric field is established between two parallel metal plates in a vacuum. Fig. 7.1 shows the path of the $\alpha$-particles as they move between the plates. The field strength between the plates is then lowered. The $\alpha$-particles are then changed to $\beta$-particles. Fig. 7.2 shows the deflection of the $\beta$-particles.
(a(i))[1]

State one similarity between the electric fields in Fig. 7.1 and Fig. 7.2.

(a(ii))[2]

The electric field strength in Fig. 7.2 is smaller than the field strength in Fig. 7.1. State two ways in which this electric field strength can be reduced.

(a(iii))[3]

Using the properties of $\alpha$-particles and $\beta$-particles, suggest three reasons for the different deflections seen in Fig. 7.1 and Fig. 7.2.

(b)[2]

Uranium-238 is a source of $\alpha$-particles. The nuclear reaction for $\alpha$-particle emission is shown by $^{238}_{92}\text{U} \rightarrow {}^{W}_{X}\text{Q} + {}^{Y}_{Z}\alpha$. State the values of $W$, $X$, $Y$ and $Z$.

(c)[1]

Phosphorus-32 is a source of $\beta$-particles. The nuclear reaction for $\beta$-particle emission is shown by $^{32}_{15}\text{P} \rightarrow {}^{A}_{B}\text{R} + {}^{C}_{D}\beta$. State the values of $A$, $B$, $C$ and $D$.

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