Chem Ch-4 QUIZ

The ion of an element has 3 positive charges. The mass number of the atom is 27

and the number of neutrons is 14. What is the number of electrons in the ion?

• 13

• 10

• 14

• 16

Which isotope is used in nuclear power plants to generate electricity?

• Cobalt 60

• Uranium 235

• Iodine 131

• Uranium 238

Why did Thomson’s Model of an atom fail?

i. It could not explain the screening of negative charges from that of positive

ii. It did not tell about the presence of electrons

iii. It did not give an idea about the discrete energy levels

iv. It explained the atom as a whole to be electrically neutral

Choose the correct option from the following:

• Only (iii)

• Both (i) & (iii)

• Only (i)

• Both (ii) & (iv)

What was the source of alpha particles in the Rutherford scattering experiment?

• Hydrogen nucleus

• Argon nucleus

• Helium nucleus

• None of these

Which of the following statements is incorrect about the structure of an atom?

i. The whole mass of an atom is concentrated in the nucleus

ii. The atom is an indivisible particle

iii. The atom as a whole is neutral

iv. All the atoms are stable in their basic state

Choose the right option among the following:

• (i) and (iii)

• only (ii)

• (ii) and (iv)

• none of these

Which of the following pairs are isobars?

• ₁₇Cl³⁵ & ₁₇Cl³⁷

• ₁₈Ar⁴⁰ & ₂₀Ca⁴⁰

• ₆C¹² & ₆C¹⁴

• None of these

Which radioactive element is used in the treatment of cancer?

• Iodine-131

• Uranium-234

• Plutonium-239

• Cobalt-60

Three elements- A, B and C have atomic number Z-1, Z, and Z+2 respectively. The compound between A and C will be:

• CA2

• CA

• C2A

• CA3

Members of which of the following have similar chemical properties?

• ISOTOPE

• ISOBAR

• ALLOTROPE

• BOTH ISOTOPE AND ISOBAR

Which of the following are true for an element?

(i) Atomic number = number of protons + number of electrons

(ii) Mass number = number of protons + number of neutrons

(iii) Atomic mass = number of protons = number of neutrons

(iv) Atomic number = number of protons = number of electrons

• (i) and (ii)

• (i) and (iii)

• (ii) and (iii)

• (ii) and (iv)