Answer:
C
) 2, 1, 2
Explanation:
The given reaction is synthesis reaction in which lithium and bromine react to form lithium bromide.
Chemical equation:
Li + Br₂ → LiBr
Balanced chemical equation:
2Li + Br₂ → 2LiBr
Step 1:
Li + Br₂ → LiBr
left hand side Right hand side
Li = 1 Li = 1
Br = 2 Br = 1
Step 2:
Li + Br₂ → 2LiBr
left hand side Right hand side
Li = 1 Li = 2
Br = 2 Br = 2
Step 3:
2Li + Br₂ → 2LiBr
left hand side Right hand side
Li = 2 Li = 2
Br = 2 Br = 2
When atoms bond together to form molecules, they share or give electrons. If the electrons are shared equally by the atoms, then there is no resulting charge and the molecule is nonpolar.
Answer : The reaction is endothermic.
Explanation :
Formula used :

where,
= change in temperature = 
Q = heat involved in the dissolution of KCl = ?
m = mass = 0.500 + 50.0 = 50.5 g
c = specific heat of resulting solution = 
Now put all the given value in the above formula, we get:


The heat involved in the dissolution of KCl is positive that means as the change in temperature decreases then the reaction is endothermic and as the change in temperature increases then the reaction is exothermic.
Hence, the reaction is endothermic.
The correct answer is Crystals.
Unlike sugar, salt is not made out of crystals, but both salt and sugar are made out of atoms, that is molecules, and can have ions.