What reaction is A+B=AB+energy exothermic decomposition or exothermic synthesis

One similarity and one difference between an element and a mixture of elements

What volume does 1.70 ×10–3 mol of chlorine gas occupy if its temperature is 20.2 °c and its pressure is 795 mm hg?

What is the magnitude of the force of gravity between to 1000 kg cars which are separated by distance of 25. 0 km on an interstate highway? the force between the two cars will be what