The answer is <span>D.when the aim is to show electron distributions in shells. This is because there are some instances when elements don't possess a regular or normal electron configuration. There are those who have special electron configurations wherein a lower subshell isn't completely filled before occupying a higher subshell. It is best to visualize such cases using the orbital notation.</span>
Given that,
Temperature, T = 1500 K
Wavelength, 
To find,
The energy of one photon of this light.
Solution,
We know that, the energy of a photon is given by the formula as follows :

So, the required energy is
.
Answer: Heating a crucible to remove water from a hydrate.
Explanation:
The options are:
a. Heating a solvent to help a solute dissolve.
b. Heating an isolated solid to dry it.
c. Heating water to boiling for a water bath.
d. Heating a crucible to remove water from a hydrate.
The procedure that can be performed on a hot plate are:
a. Heating a solvent to help a solute dissolve.
b. Heating an isolated solid to dry it.
c. Heating water to boiling for a water bath.
It should be noted that the hot plate cannot be used for heating of crucible in order to remove water from a hydrate. It is not advisable for someone to heat any silica or ceramic objects on a hot plate.
Therefore, heating a crucible to remove water from a hydrate is the correct option.
The number of sp2 hybrid orbitals on the carbon atom in CO32– is 3. Because hybrids = combination of 2 different types of orbitals
sp2 = 1/3 s character + 2/3 p character