1. If the value of n = 3,The quantum number l can have values from to .The total number of orbitals possible at the n = 3 energy level is . 2. If the value of l = 1,The quantum number ml can have values from to .The total number of orbitals possible at the l = 1 sublevel is .

1.) l = 0 to 2 ; Total number of orbitals possible at n=3 energy level is 9

2.) if l = 1, quantum number ml can have values from (-1 to 1)

Total number of orbitals possible at l = 1 sublevel is 3

Explanation:

When n= 3, which is the principal quantum number, the angular quantum number 'l' can only take values ranging from( 0 to n-1) that is, when n=3, l can range from (0,1,2). Number of orbitals in a shell is the square of the principal quantum number,. Here 3^2 = 9. A total of 9 orbitals exist in the n=3 energy level with 1 in the 3s subshell, 3 in the 3p subshell and 5 in the 3d subshell.

The magnetic quantum number ranges from (-l to +l) therefore, with l being 1, ml can range from (-1 to 1) values -1, 0, 1. The number of orbitals in a subshell is 2(l) + 1

With l = 1;

2(l) + 1

2(1) + 1 = 3

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.