Class 11th

Question Answer:

Why all isotopes of a given element show the same type of chemical behaviour?

The maximum number of electrons in a sub-shell is given by the equation
(a) n² (b) 2n² (c) 2l – 1 (d) 2l + 1

Arrange the halogens F₂, Cl₂, Br₂, I₂, in order of their increasing reactivity with alkanes. 

(i) I₂< Br₂< Cl₂< F₂

(ii) Br₂< Cl₂< F₂< I₂

(iii) F₂< Cl₂< Br₂< I₂

(iv) Br₂< I₂ < Cl₂< F₂

The energy needed to remove a single electron (most loosely bound) from an isolated – gaseous atom is called
(a) Ionisation energy (b) Electronegativity

(c) Kinetic energy (d) Electron affinity

What is value of Planck's constant in S.I. units?

(a) 6.62 x 10²⁴ Js (b) 6.62 x 10³⁴ Js (c) 6.62 x 10^-24 Js (d) 6.62 x 10^-34 Js

Arrange the following in decreasing order of their boiling points.

(A) n–butane

(B) 2–methylbutane

(C) n-pentane

(D) 2,2–dimethylpropane

(i) A > B > C > D

(ii) B > C > D > A

(iii) D > C > B > A

(iv) C > B > D > A

Which element does not have any neutron?

(a) Li (b) C (c) H (d) B

Which element does not have any neutron?

(a) Li (b) C (c) H (d) B

An alkane C₈H₁₈ is obtained as the only product on subjecting a primary alkyl halide to Wurtz reaction. On monobromination this alkane yields a single isomer of a tertiary bromide. Write the structure of alkane and the tertiary bromide.

Which one of the following statements is correct? 

(a) Fe³⁺ is more paramagnetic than Fe²⁺.

(b) Fe²⁺ is more paramagnetic than Fe³⁺.

(c) Both are equally paramagnetic.

(d) They are non-magnetic.