CBSE Class 9 Science Journey Inside the Atom (Class 9 NCERT New) Quiz 12

1. Because atoms are neutral, each positive charge is

A the same as a neutral charge. B balanced by a negative charge. C the same as no charge. D balanced by a neutral charge.

2. Which statement best describes the mass number (#) of an atom?

A the sum of electrons and neutrons in the nucleus B the sum of protons & neutrons in the nucleus C the difference in mass between protons & neutrons D the difference in mass between electrons and neutrons

3. Every neutral atom has the same number of protons and electrons, however

A they may not have the same # of neutrons. B they cannot combine with other atoms. C they cannot form isotopes. D they may also have the same atomic mass.

4. When an atom contains more electrons than protons, it is

A a neutral atom with no charge B an ion and negatively charged C an ion and positively charged D an isotope and has more mass

5. If a carbon atom has six protons and has a mass of 13 amu, how many neutrons are in that carbon atom?

A 5 B 6 C 7 D 8

6. A certain atom has 26 protons, 26 electrons, and 30 neutrons. What is its mass number?

A 26 B 30 C 52 D 56

7. What is the nucleon number of sodium?

A 11 B 23 C 12

8. What is the neutron number of the sodium atom?

A 23 B 12 C 11 D 22

9. The atom has 24 atomic mass and 14 neutrons. How many electron does it have.

A 24 B 10 C 14 D 12

10. Which of the following statements is incorrect about the structure of an atom?i. The whole mass of an atom is concentrated in the nucleusii. The atom is an indivisible particleiii. The atom as a whole is neutraliv. All the atoms are stable in their basic stateChoose the right option among the following:

A (i) and (iii) B only (ii) C (ii) and (iv) D none of these