B. Select the correct option.
1. The circular paths in which electrons revolve around the nucleus of an atom are called the
(a) Nucleons (b) protons (c) shells (d) ions.
2. The neutron was discovered by
(a) Goldstein (b) Neils Bohr (c) Air James Chadwick (d) Ernest Rutherford
3. The innermost shell of an atom can occupy (a) 8 electrons (b) 2 electrons (c) 18 electrons (d) any number of electrons
4. How many valence electrons does an atom of sodium have (a) 1 (b) 2 (c) 3 (d) 4
5. Which of the following is the correct electronic configuration of sulphur
(a) 2,8,2 (b) 2,8,4 (c) 2,8,6 (d) 2,8,8
6. An atom with atomic number 18 and mass number 40 has
(a) 18 electrons, 18 protons and 20 neutrons
(b) 18 protons, 18 electrons and 22 neutrons
(c) 18 protons, 18 electrons and 18 neutrons
(d) 18 protons, 22 electrons and 18 neutrons
7. An isotope of an element has different
(a) Mass number
(b) atomic numbers
(e) number of electrons.
(c) number of protons
Answers
Answer:
The answers are
1. shells
2. Air James Chadwick
3. 2 electrons
4. 1 electron
5. ( 2, 8, 6 )
6. 18 protons, 18 electrons and 22 neutrons
7. mass number
Hope it helps you :)
1. The circular paths in which electrons revolve around the nucleus of an atom are called the
(a) Nucleons (b) protons (c) shells (d) ions
Ans. (c) Shells
2. The neutron was discovered by
(a) Goldstein (b) Neils Bohr (c) Air James Chadwick (d) Ernest Rutherford
Ans. (c) Air James Chadwick
3. The innermost shell of an atom can occupy
(a) 8 electrons (b) 2 electrons (c) 18 electrons (d) any number of electrons
Ans. (b) 2 electrons
4. How many valence electrons does an atom of sodium have
(a) 1 (b) 2 (c) 3 (d) 4
Ans. (a) 1
5. Which of the following is the correct electronic configuration of sulphur
(a) 2,8,2 (b) 2,8,4 (c) 2,8,6 (d) 2,8,8
Ans. (c) 2,8,6
6. An atom with atomic number 18 and mass number 40 has
(a) 18 electrons, 18 protons and 20 neutrons
(b) 18 protons, 18 electrons and 22 neutrons
(c) 18 protons, 18 electrons and 18 neutrons
(d) 18 protons, 22 electrons and 18 neutrons
Ans. (b) 18 protons, 18 electrons and 22 neutrons
7. An isotope of an element has different
(a) Mass number
(b) atomic numbers
(e) number of electrons.
(c) number of protons
Ans. (a) Mass number