Answer:

Explanation:
The unbalanced nuclear equation is

Let's write X as a nuclear symbol.

The main point to remember in balancing nuclear equations is that the sums of the superscripts and of the subscripts must be the same on each side of the reaction arrow.
Then
235 = 4 + A , so A = 235 - 4 = 231, and
92 = 2 + Z , so Z = 92 - 2 = 90
And your nuclear equation becomes

Element 90 is thorium, so

Answer:
Explanation:
heat released by the solution
= 120 x 3.18 x ( 25 - 14 )
= 4197.6 J
= 4.1976 kJ
This is the heat gain by the salt
so enthalpy change = + 4.1976 kJ
because there is increase in enthalpy
It is endothermic process .
First, the symbol for sodium oxide is Na₂O
Each Na (sodium) has a charge of 1+, and each O has a charge of 2- :
Na₂¹⁺O²⁻
There are two Na's, however, and each one is 1+, however, so the Na₂ has a total charge of 2+. Because of this, the 2+ from the 2 Na's and the 2- from the O cancel each other out to make 0.
D) It is unlikely that a specific cause can be determined, but the treatment would likely be the same in either case