The unstable arrangement of atoms that forms momentarily at the peak of the activation-energy barrier is known as the what?

Iknow the answer is a but i don't know why

The boiling point of liquids is very high what does it indicate

Select the correct text in the passage. which sentences describe examples of sustainable living? i live in an old apartment building downtown, but my company is based in an office park on the outskirts of the city. i drive an old car that needs to be replaced. i plan to buy a hybrid for better gas mileage, but for now i am able to carpool with a couple of friends from work. the drive to the office park is about 45 minutes each way, but we do get to work in a modern building. the architects just received a leed certification for the design.