How many electrons can be described by the following quantum numbers: n=2, 1=-1, m-1.

6 electrons

Explanation:

The principal quantum number n; describes the energy level and here, it is 2.

The azimuthal or secondary quantum number l is given as 1, we are describing the p-orbital

The magnetic quantum number is -1, and we have 3 sub-orbitals here:

   It is a 2p-suborbital

So; in each sub orbital we have 2 electrons

The number of electrons that can be described here  =  2 x 3 = 6 electrons.

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8

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