Answer:
Both are highly reactive.
Explanation:
A has 1 valence electron D has 3
A is sodium D is aluminum
We have that energy=specific heat * change in temperature * mass. Thus, we have the final temperature (22) minus the initial temperature (55) to equal -33 as our change in temperature. Our specific heat is in J/g*C, so we're good with that because g stands for grams and the aluminium is measured in grams. As there are 10 grams of aluminum, we have

as our final temperature
An exothermic reaction would release energy and would therefore lose heat itself, while an endothermic reaction would absorb energy and gain heat. Therefore, losing heat would be an exothermic reaction
Feel free to ask further questions!
Equation: MgOH2 (s) --> MgO (s) + H2O (g)
And it's already balanced.
I had chemistry this semester too.
Answer:
The change in temperature that occurs when 8000 J of heat is used by a mass 75 g of water is 25.4 °C
Explanation:
H = mc ΔT
m = 75 g
c = 4. 200 J/ g °C
H = 8000 J
ΔT =?
Rearranging the formula, making ΔT the subject of formula;
ΔT = H / m c
ΔT = 8000 / 75 * 4.200
ΔT = 8000 / 315
ΔT = 25.4 °C
I am not sure but this is what I think
This question uses the formula connecting mass, density and volume
Which is Density= Mass/Volume
Convert the mass in g
92.5 kg = 92,500g
7.87g/ml = 92,500/ Volume
Volume= 92,500/7.87
= 11,753.5 ml
Now since we have to give the answer in liters we can just divide by 1000 and get
11.75 litres