<span>When a chemical reaction occurs and the thermometer in the container records a drop in temperature t</span>he reaction is exothermic because heat was released by the reaction.
<span>B. The reaction is exothermic because heat was released by the reaction. is your answer.
Hoped I helped!</span>
The answer is A. Improving the diet.
Answer:
B 100 cm3
Explanation:
The balanced equation is given as;
2H2(g)+ O2(g) --> 2H2O(g)
From the reaction stochiometry, 2 cm3 of H2 would react with 1 cm3 of O2 to form 2 cm3 of H2O
Before Reaction --> 100cm3 of H2, 25cm3 of O2, 0cm3 of H2O
During Reaction --> 50cm3 of H2, 25cm3 of O2, 50cm3 of H2O
(Oxygen is sed uup in the reaction)
After Reaction --> 50cm3 of H2, 0cm3 of O2, 50cm3 of H2O
Total volume left = Unreacted H2 (50cm3) + 50cm3 of H2O formed
Total Volume left = 50 + 50 = 100cm3
The number of protons is same as periodic table number.
In this case 81 Periodic table number element has 81 Protons.