what is principal quantum number?

Hi,

There are four quantum numbers, viz,

• Principal quantum number (n): It defines the main shell to which an electron belongs. The values of n =1,2,3,4,......... As n
• increases the size and energy of the orbital increases. It helps us to determine the value of the rest of the three quantum numbers .
• Azimuthal quantum number (): It tells us the number of subshells present in the main shell and the orbital to which an
• electron belongs. Its value is equal to 0 to (n-1).
• Magnetic quantum number (m): It informs the level of degeneracy of the orbitals. Its value is equal to -,0,+.
• Spin quatum number (s): It tells us whether the electron in an orbital is spinning in upward direction or downward
• direction. s has two values +1/2 for upward spin and -1/2 for downward spin.

The following table shows the values of different quatum numbers:

he following table shows the values of different quatum numbers:

=n-1

m = -,0.+

• 1 (K)

• 0 (s)

• 0

• 0

• 2 (L)

• 0 (s)
• 1 (p)

• 0
• -1,0,+1

• 0
• 3 (p_x,p_y,p_z)

• 3 (M)

• 0 (s)
• 1 (p)
• 2 (d)

• 0
• -1,0,+1
• -2,-1,0,+1,+2

• 0
• 3 (p_x,p_y,p_z)
• 5 (d_xy,d_yz,d_zx,,

• 4 (N)

• 0 (s)
• 1 (p)
• 2 (d)
• 3 (f)

• 0
• -1,0,+1
• -2,-1,0,+1,+2
• -3,-2,-1,0,+1,+2,+3

• 0
• 3 (p_x,p_y,p_z)
• 5 (d_xy,d_yz,d_zx,,
• 7 degenerate orbitals