301.

Highest energy will be absorbed to eject out the electron in the configuration.

• 1s²2s²2p¹

• 1s²2s²2p³

• 1s²2s²2p²

• 1s²2s²2p⁴

If n = 6, the correct sequence for filling of electrons will be

• ns $\to$(n - 1)d $\to$(n - 2)f $\to$np

• ns $\to$(n - 2)f $\to$np $\to$(n - 1)d

• ns $\to$np $\to$(n - 1)d $\to$(n - 2)f

• ns $\to$(n - 2)f $\to$(n - 1)d $\to$np

An electron is moving in Bohr's fourth orbit. Its de-Broglie wave length is $\mathrm{\lambda }$. What is the circumference of the fourth orbit?

• $\frac{2}{\mathrm{\lambda }}$

• 2$\mathrm{\lambda }$

• 4$\mathrm{\lambda }$ 

• $\frac{4}{\mathrm{\lambda }}$

The Vividh Bharti Station of All India Radio, Delhi, broadcasts on a frequency of 1,368 kHz (Kilohertz). Calculate the wavelength ($\mathrm{\lambda }$) of the electromagnetic radiation emitted by transmitter. Which part of the electromagnetic spectrum does it belong to?

• 319.4 m and X-rays

• 319.4 m and radiowave

• 219.3 m and microwave

• 219.3 m and radiowave

In an atom, an electron is moving with a speed of 600 m/s with an accuracy of 0.005%. Certainty with which the position of the electron can be located is

(Given, h= 6.6 x 10^-34 kg m² s^-1, mass of electron e_m = 9.1 x 10^-31 kg)

• 215 x 10^-3 m

• 2.78 x 10^-3 m

• 1.92 x 10^-3 m

• 3.24 x 10^-3 m

Maximum number of electrons in a subshell of an atom determined by the following?

• 4l + 2

• 2n²

• 4l - 2

• 2l + 1

Which one of the following sets of quantum numbers represents the highest energy level in an atom?

• n = 4; l = 0; m = 0; s = +$\frac{1}{2}$

• n = 3; l = 1; m = 1; s = +$\frac{1}{2}$

• n = 3; l = 2; m = -2; s = +$\frac{1}{2}$

• n = 3; l = 0; m = 0; s = +$\frac{1}{2}$

The ratio of the difference in energy between the first and the second Bohr orbit to that between the second and the third Bohr orbit is

• $\frac{1}{2}$

• $\frac{1}{3}$

• $\frac{4}{9}$

• $\frac{27}{5}$

Which of the following has the maximum number of unpaired electrons?

• V³⁺

• Fe²⁺

• Mn²⁺

• Cu⁺

The geometry of XeF₆ is

• planar hexagon

• regular octahedron

• distorted octahedron

• square bipyramid