Uses of Radioactivity

Q.

Nuclear energy can be termed in both renewable and non renewable resources.Why?

Q.

Name the isotope used in the treatment of cancer.

Q.

Give four examples of radioactive substances? [2 MARKS]

Q.

Which of the following is true regarding nuclear force?

1. It is the strongest of the fundamental forces

2. It depends on the magnitude of the charge on the interacting particles.

3. It is a short range force.

4. It is due to the interaction between protons and electrons.

Q. Which of the following is a short range force?

1. Nuclear Force
2. Electrostatic Force
3. Both of these
4. Neither of these

Q.

During the emission of $\mathrm{\beta }$-particle , the ___________ number remains the same.

Q. The process in which, the nuclei of atoms are bombarded with alpha particles to create radioactive isotopes is called nuclear .

1. destruction
2. transmutation
3. disintegration

Q. The count rate observed from a radioactive source at $t$ second was $N_0$ and at $4t$ second it was $\frac{N_0}{16}$. The count rate observed at $\left(\frac{11}{2}\right)t$ second will be

1. $\frac{N_0}{128}$
2. $\frac{N_0}{64}$
3. $\frac{N_0}{32}$
4. $Noneofthese$

Q. the isotopic abundance of c-12 & C -14 is 98% & 2% respectively. what would be the no. of c-14 isotope in 12gC sample?

Q.

One harmful effect of radioactivity is:

1. Radioactivity can kill the living tissues of human beings and cause radiation burns

2. Radioactivity can spread air borne diseases

3. Radioactivity can be poisonous if inhaled

4. Radioactivity can harm bones and hair of human beings and animals

Q. Why Strong nuclear force does not follow inverse Square Rule?

Q. The radioactive isotope used in the treatment of cancer has to be a good source of ________ radiations.

1. $\beta$
2. $\alpha$
3. $\gamma$
4. $IR$

Q.

What are the advantages of nuclear energy? [3 MARKS]

Q. The half life of a radioactive substance is 20 minutes. The approximate time interval $(t_2-t_1)$ between the time $t_2$ when $\frac{2}{3}$ of it has decayed and time $t_1$ when $\frac{1}{3}$ of it had decayed is:

1. 7 min
2. 14 min
3. 20 min
4. 28 min

Q. How much energy is realesed in Uranium 235 fission reaction?

Q. Which of the following is used by an archaeologist to determine the age of an artifact, in percentage?

1. $Phosphorus-31$
2. $Carbon-14$
3. $Chlorine-37$
4. $Hydrogen-3$
5. $Bromine-81$

Q. A radio nucleus ${}_Z{X}^A$ emits an alpha particle and becomes Y. Mention the atomic number and mass number of Y. What do you call the conversion of one element into another element?

Q. A freshly prepared sample of a radioisotope of half-life $1386s$ has activity ${10}^{3}disintegrationspersecond.$ Given that $\ell n2=0.693,$ the fraction of the initial number of nuclei (expressed in nearest integer percentage) that will decay in the first $80s$ after preparation of the sample is:

1. $1$%
2. $2$%
3. $3$%
4. $4$%

Q. A radioactive isotope that is to be used in the treatment of cancer should be a good source of gamma-ray radiations.

1. True
2. False

Q. The strong nuclear force is:

1. Always Attractive
2. Always Repulsive
3. Attractive when nucleons are very close and vice versa
4. Repulsive when nucleons are very close and vice versa

Q.

Nuclei with same number of protons but different number of neutrons are called ___.

Nuclei with same number of neutrons but different atomic number are called ___.

Nuclei with same mass number are called ___.

Q. In which one of the following regions of the electromagnetic spectrum will the vibrational motion of molecules give rise to absorption?

1. Ultraviolet
2. Microwaves
3. Infrared
4. Radio waves

Q. Which of the following are uses of radioactive substances?

1. Use as projectiles and tracers for various scientific studies
2. To make luminescent signs
3. To kill malignant tumor
4. All of the above

Q. Rate of decay of radioactive substance is altered by :

1. pressure
2. temperature
3. chemical change
4. none of the above

Q. What is the power output of ${}_{92}{U}^{235}$ reactor if it takes $30$ days to use $2kg$ of fuel, and if each fission gives $185MeV$ of usable energy

1. $50.48MW$
2. $46.58MW$
3. $36.58MW$
4. $58.46MW$

Q. Which of the following is a radioactive substance?

1. Uranium
2. Radium
3. Thorium
4. All of the above

Q. Radioactive elements emits nuclear radiations.

1. True
2. False

Q. A radioactive isotope has a half-life of $T$ years.How long will it take the activity to reduce to $1\%$ of its original value?

1. $4.64T$
2. $6.64T$
3. $4.46T$
4. $6.46T$

Q. Select the wrong statement(s).

1. Nuclear isomers contain the same number of protons and neutrons
2. The decay constant is independent of the amount of the substance taken
3. $1$ curie $=3.7\times {10}^{10}dis$
4. Actinium series starts with ${}^{238}U$

Q.

Who named Uranium?