I think the correct answer from the choices listed above is option D. the substances cobalt and barium chloride will not react since cobalt os less active than barium so it does not have enough energy to displace barium in the compound. Hope this answers the question.
I’m pretty sure it’s D because energy measures the kinetic, thermal, electrical, chemical, nuclear and other forms.
1 mol = 6.022 x 10²³ atoms
In order to find how many atoms, dimly multiply the amount of moles you have by 6.022 x 10²³ or Avogadro's number.
So you have 1.75 mol CHC1₃ x (6.022x10²³) = 1.05385 x 10²⁴ atoms of CHCl₃
But now you have to round because of the rules of significant figures so you get 1.05 x 10²⁴ atoms of CHCl₃
