Class 11th

The nuclear charge experienced by electrons depends on the distance between the nucleus and orbital. The greater is this distance, the lesser is the effective nuclear charge. Among all the p orbitals, 4p orbital lies the farthest from the nucleus and thus experiences the lowest effective nuclear charge because of the maximum magnitude of screening or shielding effect.

This is a short answer type question as classified in NCERT Exemplar

Due to the +R effect halogens are ortho and para directing groups.

The electrons may be assigned to the following orbitals :
(i) 4d
(ii) 3d
(iii) 4p
(iv) 3d
(v) 3p
(vi) 4p.
The increasing order of energy is :
(v) < (ii) = (iv) < (vi) = (iii) < (i)

Since actual momentum is smaller than the uncertainty in measuring momentum, therefore, the momentum of electron cannot be defined

This is a short answer type question as classified in NCERT Exemplar

The electron donating group increases the reactivity in electrophilic substitution reaction whereas the electron withdrawing group decreases the reactivity in electrophilic substitution.

Thus, the order of reactivity

ν = 4.37 x 10⁵ m s^-1, m = 0.1 kg

As per de Brogile's equation,

λ= m/v = (6.626 x 10^-34 kg m² s^-1) / (0.1 kg) x (4.37 x 10⁵ m s^-1)

=6.626/0.437  x 10^-34-5 m

= 1.516 x 10^-38 m

This is a short answer type question as classified in NCERT Exemplar

ν = 2.19 x 10⁶ m s^-1

As per de Brogile's equation,

λ= m/v = (6.626 x 10^-34 kg m² s^-1) / (9.1 x 10^-31 kg) x (2.19 x 10⁶ m s^-1)

6.626/91 * 2.19=  x 10^-34+25 m = 0.33243 x 10^-9 m = 332.43 pm

λ = 800 pm = 800 x 10^-12 m

m = 1.675 x 10^-27 kg

As per de Brogile's equation,

ν =h/mλ  = (6.626 x 10^-34 kg m² s^-1) / (1.675 x 10^-27 kg) x (800 x 10^-12 m)

=6.626/1.675 * 8  x 10^-34+27+10

= 0.494 x 10³ ms^-1

= 494 ms^-1