Answer:
I guess B They have a charge
It’s a molecule hope this helps
Answer:
The value is 
Explanation:
From the question
The equation given is
NiO(s) + H2(g) ⇌ Ni(s) + H2O(g) Kc=40 (1)
NiO(s) +CO(g) ⇌ Ni(s) +CO2(g) Kc=600 (2)
Generally the reverse of the second equation as shown below
Ni(s) +CO2(g) ⇌ NiO(s) + CO(g) (3)
The equilibrium constant becomes 
Now adding 1 and 3 we obtain
NiO(s) + H2(g)+ Ni(s) +CO2(g) ⇌ Ni(s) + H2O(g)+NiO(s) + CO(g)
CO2(g) + H2(g) ⇌ CO(g) + H2O(g)
Hence the equilibrium constant for the resulting equation is mathematically evaluated as
=> 
=>
Elements of Group 1 and group 2 in the periodic
table contain elements so reactive that they are never found in the free state
<u>Explanation</u>:
The metals in group 1 of periodic table consisting of 'alkali metals' which include lithium, potassium, sodium, rubidium, Francium and caesium. They are highly reactive because they have low ionisation energy and larger radius. The group 2 metals consist of 'alkaline earth metals' which include calcium, strontium, barium, beryllium, radium and magnesium. These alkaline earth metal have +2 oxidation number, hence are highly reactive.
These both group metals are mostly reactive and so are never found in a free state. When they are exposed to air they would immediately react with oxygen. Hence, are stored in oils to avoid oxidation.
