My Answer: (Ar) 3d10 4s2 4p5
Hope I helped! :D
Explanation:
The pure form of water has a boiling point of 100°C. Boiling point is a physical property of matter and it shows that at such temperature, a liquid substance will change state to vapor.
Pure water is made up of 2 atoms of hydrogen and 1 atom of oxygen. The only intermolecular forces between them is the hydrogen bonds that must be broken for the water to boiling off.
In hydrate, water is present in another form. The water is attached to another compound.
For a pure liquid, the they have reasonably constant boiling point and low boiling range.
Impurities such as the other part of the hydrate causes the elevation of the boiling point and the widening of the boiling range for impure substances.
We are no longer dealing with just hydrogen bonds, other molecular interactions are now involved and they need to be accounted for.
learn more:
Pure substances brainly.com/question/1832352
#learnwithBrainly
Fixed vs Variable Oxidation is given below.
Explanation:
1.In its compounds, hydrogen has an oxidation number of +1, except. hydrides where the. oxidation number of hydrogen is -1. In their compounds, the metals with fixed oxidation states have the oxidation number that. corresponds with the fixed oxidation number.
A variable oxidation state is a value that determines the charge of the atom depending on certain conditions.
2. Oxidation state of elements is considered to be of the most important in the study of chemistry. For some elements, this figure is constant known as fixed oxidation , while for others it is variable is called variable oxidation state.
3. MgCl2 : magnesium is in Group IIA and all elements in Group IIA have fixed oxidation numbers of +2
FeCl2 : iron has a variable oxidation number of either +2 or +3 and is not fixed
Sorry, but where are the ‘items’?
Answer: b. 
is positive and 
is positive.
Explanation:-
As the temperature of the pack drops, the energy has been absorbed from the pack for dissolution of 
in water. Thus as the energy has been absorbed in the reaction, the reaction is endothermic and the change in enthalpy i.e. is positive.
The entropy is the measure of degree of randomness. The entropy increases when the randomness increases and the entropy decreases when the randomness decreases. When a substance dissolves in water, it dissociate into ions and hence the randomness increases thus the change in entropy i.e. is positive.
