Which combinations of n and l represent real orbitals, and which do not exist a) 2s b) 3p c) 5s d) 1d

Answer : The combinations of n and l don not exist is, (d) 1d

Explanation :

Principle Quantum Numbers : It describes the size of the orbital and the energy level. It is represented by n. Where, n = 1,2,3,4

Azimuthal Quantum Number : It describes the shape of the orbital. It is represented as 'l'. The value of l ranges from 0 to (n-1). For l = 0,1,2,3... the orbitals are s, p, d, f...

(a) For 2s :  

n=2 and l can have value 0 to (n-1) i.e. 0 and 1 only. For s, l=0 which is possible.

(b) For 3p :  

n=3 and l can have value 0 to (n-1) i.e. 0, 1 and 2 only. For p, l=1 which is possible.

(c) For 5s :  

n=1 and l can have value 0 to (n-1) i.e. 0, 1, 2, 3 and 4 only. For s, l=0 which is possible.

(d) For 1d :  

n=1 and l can have value 0 to (n-1) i.e. 0 only. For d, l=2 which is not possible.

Hence, the combinations of n and l don not exist is, (d) 1d

conduction is the transfer of thermal energy (heat in transfer) due to collisions between the molecules in the object. collisions between adjacent atoms and molecules transfer kinetic energy from the warmer to the cooler object. the objects must be in physical contact.