What role does activation energy play in an exothermic reaction? can someone pls help me w this :)

Suppose the universe were completely empty except for one object-a solid sphere moving through space of 100 km/s. what sort of path would the object be moving in? explain your answer

Δu of , in kj/kg, as it isto k, (a)as a of , (b) at , (c) at .

Which is true about metals used for jewelry, such as platinum and gold? a. they have low flammability. b. they have low reactivity. c. they have high flammability. d. they have high reactivity.