Element X has two isotopes: X-79 (59.69% abundance) and X-81 (40.31% abundance). Calculate the atomic weight of Element X. Type in ALL your work including your final answer with correct unit & significant figures.

Temperature and kinetic energy are proportional. a) adirectly b) directly c) indirectly

Answer explain why it is not possible to deduce a complete order of reactivity.

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?