An atom has 18 protons and 8 valance electrons. Which statement would best identify this elementa A. The element is highly reactive with eight electrons in its outer shell. B. The element has an atomic mass of 18. C. The element is "happy" or stable because it outer energylevel is filled. D. The element is a metal.

The earth remains in orbit around the sun due to the force of gravity. how does the force of gravity exerted by the sun on the earth compare to the force of gravity exerted by the earth on the sun?

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.

For most stars, what does a higher temperature tend to to with? a lower luminosity a higher luminositya red color none of the above