Which of these activities performed by a chemist is primarily based on an understanding of physics?

How do hydroponic plants differ from nonhydroponic plants? a.) hydroponic plants can grow in a dryer soil. nonhydroponic plants grow in moist soil. b.) hydroponic plants grow on other plants and are known as air plants. nonhydroponic plants do not grow on other plants. c.) hydroponic plants can only grow in rain forests. nonhydroponic plants cannot grow in rain forests. d.) hydroponic plants are grown without soil. nonhydroponic plants are grown in soil.

In a thunderstorm, charge builds up on the water droplets or ice crystals in a cloud. thus, the charge can be considered to be distributed uniformly throughout the cloud. for the purposes of this problem, take the cloud to be a sphere of diameter 1.00 kilometer. the point of this problem is to estimate the maximum amount of charge that this cloud can contain, assuming that the charge builds up until the electric field at the surface of the cloud reaches the value at which the surrounding air breaks down. this breakdown means that the air becomes highly ionized, enabling it to conduct the charge from the cloud to the ground or another nearby cloud. the ionized air will then emit light due to the recombination of the electrons and atoms to form excited molecules that radiate light. in addition, the large current will heat up the air, resulting in its rapid expansion. these two phenomena account for the appearance of lightning and the sound of thunder. take the breakdown electric field of air to be eb=3.00ă—106n/c. part a estimate the total charge q on the cloud when the breakdown of the surrounding air is reached. express your answer numerically, to three significant figures, using ďµ0=8.85ă—10â’12c2/(nâ‹…m2) .

How does the amount of energy required to hold each proton and neutron in the nucleus compare to the energy released when they are removed?