If the spin of one electron in an orbital is clockwise , what is the spin of the other electron in that orbital

Spin Quantum Number is the fourth quantum number for electrons. The electron spin is either clockwise, denoted by (+1/2) or it can be anti-clockwise, denoted by -(1/2). If the spin of one electron is clockwise, in an orbital, then other electron will have anti-clockwise spin.

According to the Pauli's exclusion principle, the electrons cannot have same similar quantum numbers. The four quantum numbers are:

For example, if an electron is filled in 1s orbital, the values of four quantum numbers will be:

Noe, according to the Pauli's principle, two unique set for electron in 1s orbital will be:

Therefore, the electrons in the orbital are filled in clock-wise and anti-clockwise direction. No two electrons in an orbital have same spin number.

To know more about spin number, refer tot he following link:

link

Here we have to get the spin of the other electron present in a orbital which already have an electron which has clockwise spin.

The electron will have anti-clockwise notation.

We know from the Pauli exclusion principle, no two electrons in an atom can have all the four quantum numbers i.e. principal quantum number (n), azimuthal quantum number (l), magnetic quantum number (m) and spin quantum number (s) same. The importance of the principle also restrict the possible number of electrons may be present in a particular orbital.

Let assume for an 1s orbital the possible values of four quantum numbers are n = 1, l = 0, m = 0 and s = .

The exclusion principle at once tells us that there may be only two unique sets of these quantum numbers:

1, 0, 0, + and 1, 0, 0, -.

Thus if one electron in an orbital has clockwise spin the other electron will must be have anti-clockwise spin.    

the correct answer is:

a. formation of precipitation