Magnesium reacts with an element (X) to form an ionic compound. If the ground state electronic configuration of (X) is 1s² 2s² 2p³, the simplest formula for this compound is

• Mg₂X₃

• MgX₂

• Mg₃X₂

• Mg₂X

552.

Among the following set of quantum numbers, the impossible set is

• n	l	m	s
  3	2	-3	-1/2

• n	l	m	s
  4	0	0	1/2

• n	l	m	s
  5	3	0	-1/2

• n	l	m	s
  3	2	-2	1/2

Match the type of series given in Column I with the wavelength range given in Column II and choose the correct option.

Column I		Column II
A	Lyman	1.	Ultraviolet
B.	Paschen	2.	Near-infrared
C.	Balmer	3.	Far Infrared
D.	Pfund	4.	Visible

• A	B	C	D
  1	2	4	3

• A	B	C	D
  4	3	1	2

• A	B	C	D
  3	1	2	4

• A	B	C	D
  4	3	2	1

The electrons identified by quantum numbers n and l, are as follows

1. n =4, l=1

2. n = 4, l = 0

3. n =3, l= 2

4. n = 3, l = 1

If we arrange them in order of increasing energy, i.e., from lowest to highest, the correct order is

• IV<II<III<I

• II<IV<I<III

• I < III < II < IV

• III < I < IV < II

What will be the number of waves formed by a Bohr electron in one complete revolution in its second orbit?

• Three

• Two

• One

• Zero

Match the particle with its characteristic

Column I	Column II
A. $\mathrm{\alpha }$-particle	p. Slow moving
B. Isobar	q. High penetration power
C. $\mathrm{\gamma }$- ray	r. Same atomic mass
D. $\mathrm{\beta }$- particle	s. consists of electron

• A - p; B - r; C - q; D - s

• A - p; B - q; C - r; D - s

• A - r; B - s; C - p; D - q

• A - s; B - r; C - p; D - q

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