Isotopes MCQ with Answers Pdf: 

• Atoms containing the same number of protons, but differing in the content of neutrons are called isotopes (from the Greek iso – the same, tope – place).
• Isotopes have the same chemical properties and occupy the same place in the periodic table of Mendeleev. 
• Depending on the atomic mass M, indicated to the left of the element symbol, isotopes can be stable or radioactive (radioisotopes).
• Stable isotopes can be used by measuring their volumes and proportions in samples, such as water samples. Natural stable isotopes, found in water and other substances, are used to track origins, history, sources, sinks, and interactions in the water and carbon-nitrogen cycles.
• Unstable isotopes are used as sources of radioactive (α-, β-, γ- and neutron) radiation used to solve practical problems in various fields of science and technology. 
• In biology, mutations in living organisms are induced by radioactive radiation.
• Various isotopes of chemical elements are widely used in scientific research, in various fields of industry and agriculture, in nuclear energy, modern biology, and medicine, in environmental studies, and in other areas.

1. What are isotopes?

A. Isotopes are elements having the same atomic number but differ in their mass number and chemical characteristics.

B. Elements having the same atomic number but different mass numbers are called Isotopes 

C. Both of these 

D. None of these 

Answer: C

2. Elements having the same atomic number but different mass numbers are called______

A. isotones

B. isotopes

C.isobars

D. none of the above

Answer: B

3. Isotopes have same_______

A. atomic mass

B. atomic number

C. neutrons

D. none of above

Answer: B

4. Which of the following statements about isotopes is correct_______

A. Isotopes have the same chemical properties

B. Isotopes have the same number of nucleons

C. Isotopes have the same number of protons

D. Both A and C

Answer: D

5. The number of isotopes that an oxygen atom has is_________

A. three

B. five

C. nine

D. two

Answer: A

6. Which of the following statements about radioisotopes is correct______

A. Like radioactive elements, radioisotopes have a certain half-life, and the law of decay is the same

B. The decay of radioisotopes can produce another new element

C. Radioisotopes can only be produced by natural decay and cannot be measured by artificial methods

D. The above statement is not correct

Answer: A

7. The properties in which isotopes differ are_____________

A. Chemical

B. Physical

C. electrical

D. mechanical

Answer: B

8. Hydrogen has three isotopes, protium, deuterium, and tritium.

A. They have the same number of protons

B. They have the same number of extranuclear electrons

C. They have the same number of nucleons

D. Both A and B

Answer: D

9. Isotopes of a neutral atom have______

A. an equal number of neutrons

B. a different number of protons

C. the same mass numbers

D. the same number of electrons

Answer: D

10. Which of the following statements about isotopes is correct________

A. Several isotopes of an element have the same position in the periodic table

B. Several isotopes of an element have the same chemical and physical properties

C. Atoms called isotopes to contain the same number of protons

D. Both A and C

Answer: D

11. Radioisotopes are used as tracer atoms, mainly because_______

A. Radioisotopes do not change their chemical properties  

B. The half-lives of radioisotopes are much shorter than those of naturally occurring radioactive elements  

C. The half-life has nothing to do with the physical or chemical state of the element  

D. All of these 

Answer: D

12. Deuterium is an isotope of a hydrogen atom. It contains______

A. one neutron and two protons

B. no neutrons and one proton

C. one proton and one neutron

D. one electron and two neutron

Answer: C

13. For two isotopes of the same element, in the nucleus______

A. have the same number of nucleons  

B. The number of protons is the same, but the number of neutrons is different  

C. The number of protons is different and the number of neutrons is different  

D. Atoms have the same mass number

Answer: B

14. Which of the following statements about 12 C and 14 C is correct_______

A. They have the same number of protons    

B. They have the same chemical properties  

C. They are in the same position in the periodic table of elements

D. All of these 

Answer: D