物理原子模型 DSE、CE 選擇題（第 2 頁）

11.

Which of the following is/are application(s) of radioactivity ?

(1)to estimate the age of ancient remains

(2)to kill bacteria in food

(3)to transmit signals over long distances

12.

Radium ( ${}^{226}_{88}\mathrm{Ra}$ ) decays by emitting an $\alpha$ particle to form a product nucleus $X$ . Which of the following shows the correct equation for this decay ?

13.

The below shows part of a radioactive series. $P\xrightarrow{\alpha}Q\xrightarrow{\beta}R\xrightarrow{\beta}S$ Which of the following nuclei are isotopes of the same element ?

14.

Grid of mass number A (233 to 237) against atomic number Z (90 to 93) with points R, Q, S, P and Np

The above diagram shows the mass number $A$ and atomic number $Z$ of a few nuclides. The isotope of neptunium (Np) shown decays by emitting an $\alpha$ particle and then a $\beta$ particle. Which of the following represents the resulting nuclide ?

15.

Which of the following applications of radioactivity makes use of the fact that a radioactive nuclide has a constant half-life ?

16.

A nucleus $X$ emits a beta particle to form a daughter nucleus $Y$ . Which of the following statements is/are correct ?

(1)

X

and

Y

have the same number of neutrons.

(2)The number of protons in

X

is greater than that in

Y

by

1

.

(3)The total numbers of neutrons and protons in

X

and

Y

are equal.

17.

Thickness gauge: a radioactive source above and a detector below an aluminium sheet moving between rollers

In a factory producing aluminium sheets of $1$ mm thickness, a thickness gauge is used to monitor the thickness of aluminium sheets. Which of the following states the correct radioactive source to be used in the thickness gauge and the reason behind ?

	Source	Reason
	$\alpha$	The amount of $\alpha$ particles passing through aluminium depends on its thickness.
	$\beta$	The amount of $\beta$ particles passing through aluminium depends on its thickness.
	$\beta$	$\beta$ particles are less harmful to human beings.
	$\gamma$	$\gamma$ radiation has the greatest penetrating power.

18.

Which of the following is not an application of radioactivity ?

19.

A radioactive nuclide $W$ decays to a nuclide $Z$ by emitting one $\alpha$ -particle and two $\beta$ -particles as shown below.

$W\xrightarrow{\beta}X\xrightarrow{\alpha}Y\xrightarrow{\beta}Z$

Which of the following statements about nuclides $W$ , $X$ , $Y$ and $Z$ is/are correct ?

(1)

W

and

Z

are isotopes.

(2)

X

has the greatest atomic number.

(3)

Y

has the greatest mass number.

20.

Which of the following symbols represents a neutron ?