Chemistry (Part-1)

Total Questions: 69

31. The mass of an electron is nearly one upon times that of a proton. [S.S.C. JE Electrical Exam 24.03.2021]

Correct Answer: (c) 2000
Solution:

The mass of a proton is approximately 1836 times the mass of an electron. Therefore, the mass of an electron is nearly one upon 1836 times that of a proton.

32. The mass of Proton and mass of same is: [S.S.C. Online CHSL (T-1) 11.01.2017]

Correct Answer: (a) Neutron
Solution:

The mass of a proton and that of a neutron are almost the same.
Mass of proton 1.67 × 10⁻²⁷ kg
Mass of neutron = 1.67 × 10⁻²⁷ kg
Mass of electron = 9.10 x 10⁻³¹ kg

33. What is the charge on a neutron? [S.S.C. Online CHSL (T-I) 15.03.2018]

Correct Answer: (c) No charge
Solution:

Neutrons have no charge. It is an electrically neutral particle. It was discovered by scientist Chadwick in the year 1932. It is present in the atomic nucleus along with protons.

34. The absolute charge of the electron is: [S.S.C. Online MTS (T-I) 5.10.2017]

Correct Answer: (c) 1.6 × 10⁻¹⁹ × C
Solution:

An electron is a negatively charged particle found in an atom with a negative charge equivalent to 1.6 × 10⁻¹⁹ × C .

35. The size of the nucleus is approximately: [S.S.C. Online MTS (T-I) 9.10.2017]

Correct Answer: (d) None of these
Solution:

The diameter of an atomic nucleus ranges from about 1.6 femtometers () for a single proton (the nucleus of hydrogen) to about 15 femtometers for the heaviest atoms like uranium.

This is significantly smaller than the size of the atom itself, which has a radius on the order of 10⁻¹⁰m. Hence the correct option is (d) None of these.

36. If the size of the nucleus of an atom is compared with a cricket ball, then the radius of the atom is approximately equal to how many kilometres? [S.S.C. Online CPO S.I. (T-I) 23.11.2020]

Correct Answer: (d) 5 km
Solution:

As we know, the Diameter of the cricket ball (Nucleus) is 10 cm. So the size of the Nucleus is about  while the size of an atom is 10⁻¹⁰m. Therefore, The radius of the atom is approximately equal to 5 km.

37. Atomic number of which of the following elements is greater than that of Magnesium? [S.S.C. Online CHSL (T-I) 24.01.2017]

Correct Answer: (d) Aluminium
Solution:

The atomic number of Magnesium (Mg) is 12. 

Neon (Ne) has an atomic number of 10.
Fluorine (F) has an atomic number of 9.
Sodium (Na) has an atomic number of 11.
Aluminium (Al) has an atomic number of 13.

Comparing these atomic numbers with that of Magnesium (12), we can see that only Aluminium has a greater atomic number. 

Therefore, the atomic number of (d) Aluminium is greater than that of Magnesium. 

38. Atoms of which of the following elements have more than one electron in their outermost shell? [S.S.C. JE Civil Exam 23.03.2021]

Correct Answer: (d) Beryllium
Solution:

Lithium (Li) has an atomic number of 3. Its electronic configuration is . It has 1 electron in its outermost shell (the second shell). 

Sodium (Na) has an atomic number of 11. Its electronic configuration is . It has 1 electron in its outermost shell (the third shell). 

Hydrogen (H) has an atomic number of 1. Its electronic configuration is . It has 1 electron in its outermost shell (the first shell).

Beryllium (Be) has an atomic number of 4. Its electronic configuration is . It has 2 electrons in its outermost shell (the second shell). 
Therefore, the atom of (d) Beryllium has more than one electron in its outermost shell.  

39. Neutrons are present in the nucleus of all atoms EXCEPT in those of _______. [S.S.C. JE Civil Exam 23.03.2021]

Correct Answer: (c) Hydrogen
Solution:

Neutrons are present in the nuclei of all atoms except hydrogen (H). Its atomic number is 1. Hydrogen is the lightest element. Hydrogen is a colorless, odourless, tasteless, and flammable gas. The valency of hydrogen is 1.

40. Atomic number of which of the following elements is greater than that of Neon? [S.S.C. Online CHL (T-I) 30.01.2017]

Correct Answer: (b) Magnesium
Solution:

The atomic number of Neon (Ne) is 10.

  • Oxygen (O) has an atomic number of 8.
  • Magnesium (Mg) has an atomic number of 12.
  • Nitrogen (N) has an atomic number of 7.
  • Boron (B) has an atomic number of 5.

Comparing these values to the atomic number of Neon (10), we find that only Magnesium has a greater atomic number.