Which of the following quantum numbers describes a d-orbital in the fourth energy level? a. n = 4, l = 0, m = 0              
b. n = 3, l = 1, m = 0
c. n = 3, l = -1, m = 0          
d. n = 4, l = 2, m = 0

d. n = 4, l = 2, m = 0

Explanation:

A d-orbital in the fourth energy level can only be represented by  n = 4, l = 2, m = 0.

n is the principal quantum number(n) which signifies the energy level, here it is 4;

l is the azimuthal quantum number or l which signifies the shape of the subshell, it takes a value of n - 1, 0,1,2 or 3

m is the magnetic quantum number(m) which can be -2, -1, 0, 1 , 2

So, the right and fitting solution is  n = 4, l = 2, m = 0

8 carbon atoms forming single bonds with 18 hydrogen atoms; a triple bond exists between the third and fourth carbon atom from the right

explanation:

the dissociation of nickel hydroxide is follows:

the concentration of hydroxide ion is

the equilibrium constant value of nickel hydroxide is = 6.1 * 10^-^1^6 and thus equilibrium equation can be written as:

thus, concentration of ni is 0.23 * 10^-^4 mol /l