Answer: Option (c) is the correct answer.
Explanation:
When a system is open then there will be exchange of energy between the system and surrounding.
Whereas when a system is closed then there will be no exchange of energy, that is, thermal energy will not flow into the atmosphere.
Thus, we can conclude that a sealed calorimeter is a closed system because thermal energy is not transferred to the environment.
222 grams of calcium chloride is produced.
<h3><u>Explanation</u>:</h3>
The mole concept and the chemical equation are very much closely related with each other. In the chemical reaction, the compounds or elements in both sides are balanced according to the number of atoms of each side of the reaction. So from there we can easily find the amount of reactant reacts to produce desired product.
Here we can see that 2 moles of sodium chloride produces 1 mole of calcium chloride.
So, 4 moles of sodium chloride will produce 2 moles of calcium chloride.
Now, atomic weight of calcium =40.
Atomic weight of chlorine =35.5.
So,the molecular weight of calcium chloride = 
=111.
It means, 1 mole of calcium chloride weighs 111 grams.
So 2 moles of calcium chloride weighs 
grams = 222 grams.
Atoms have electrons filled in energy shells.
1. H - hydrogen atom has one electron in the First energy shell. Therefore hydrogen has a partially filled first energy shell
2.Li - Li electron configuration is 2,1
The outermost energy shell is the second energy shell in which there is only one electron
Therefore the second energy shell is partially filled. This is the correct answer
3. K - electron configuration is 2,8,8,1
The outermost energy shell is the fourth energy shell which is partially filled. The second energy shell is completely filled
4.Na - electron configuration is 2,8,1
The outermost energy shell is the third energy shell which is partially filled
Second energy shell is completely filled
From the given options Li is the only element with a partially filled second energy shell
Answer is Li
