Answer:
Option B. A
Explanation:
From the question given above, the following data were obtained:
C(s) + 2H₂ (g) —> CH₄ (g). ΔH = –74.9 kJ
From the reaction above, we can see that the enthalpy change (ΔH) is negative (i.e –74.9 KJ) which implies that the heat content of the reactants is greater than the heat content of the products. Thus, the reaction is exothermic reaction.
For an exothermic reaction, the energy profile diagram is drawn in such a way that the heat content of reactants is higher than the heat content of products because the enthalpy change
(ΔH) is always negative.
Thus, diagram A (i.e option B) gives the correct answer to the question.
Option A is the correct option.
In terms of the collision theory, increasing the concentration of a reactant increases in the number of collisions between the reacting species per second and therefore increases the reaction rate.
Answer:
chlorine (ci)
hope you get ur answer ❤️❤️❤️❤️☺️✨
18 g of silicon-32 will be present in 800 years.
A radioactive half-life refers to the amount of time it takes for half of the original isotope to decay and it's given by

where,
quantity of the substance remaining
the initial quantity of the substance
time elapsed
the half-life of the substance
From the given information we know:
The initial quantity of silicon-32 is 40 g.
The time elapsed is 800 years.
The half-life of silicone-32 is 710 years.
So, using the calculation above, we can determine how much silicon-32 is left.

Therefore,18 g of silicon-32 will be present in 800 years.
Learn more about half-life here:
brainly.com/question/25750315
#SPJ4