Achemical reaction gives off 1,500 kj of heat energy. about how many calories is this? (1 calorie = 4.18 joules)
a. 3.6 x 10^5 calories
b. 3.6 x 10^2 calories
c. 3.6 x 10^3 calories
d. 3.6 x 10^4 calories

Adeuteron, 21h, is the nucleus of a hydrogen isotope and consists of one proton and one neutron. the plasma of deuterons in a nuclear fusion reactor must be heated to about 3.02×108 k . what is the rms speed of the deuterons? express your answer using two significant figures.

In water, a strong acid will break down into its component parts. a. completely b. partly c. never in water, a weak base will break down into its component parts. a. completely b. partly c. never

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?