The rate of change in the amount of silver supplied is equal to the ratio of the difference in the amount supplied to the number of years elapsed from 2005 to 2008. That is,
rate of change = (25 - 200) / (2008 - 2005) = -173/3
The answer is letter A.
<u>Answer:</u>
Exothermic Reaction are those reaction, in which energy is released while in endothermic reaction are those, in which energy is absorbed.
<u>Explanation:</u>
First Reaction:
As in this reaction, energy is released
½H2(g) + ½I2(g) → HI(g), ΔH = +6.2 kcal/mole
so it is <em>exothermic reaction</em>
Second reaction:
As in this reaction, energy is absorbed
21.0 kcal/mole + C(s) + 2S(s) → CS2(l)
so it is <em>endothermic reactions</em>.
Explanation:
I think 1) acidic solution
2) basic solution.
K + S = K2S
Potassium reacts with sulfur to produce potassium sulfide