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

a non redox reaction occurs when there is not a transfer of electrons. for redox reactions, which are reduction-oxidation reactions, a change in the oxidation number occurs. elements that are reduced gain electrons, and elements that are oxidized lose electrons.

explanation:

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.