PLS HELP The particles of a substance can have kinetic energy
(KE) and potential energy (PE). Which equation best
summarizes the internal energy (U) of the substance?
A. U = PEtranslation + PEvibration + PErotation +
KEintermolecular forces
B. U = PEtranslation + PEvibration + PErotation
KEintermolecular forces
C. U = KEtranslation + KEvibration + KErotation
PEintermolecular forces
D. U = KEtranslation + KEvibration + KErotation +
PEintermolecular forces

This is important 1. what happens to the speed of molecules in water vapor when it condenses to form a liquid? (2 points) the molecules slow down. the molecules speed up. the molecules slow down and then speed up. the molecules speed up and then slow down. 2. how might human activities change to compensate for a decrease in water supplies? (2 points) humans might build a factory. humans might build drainage systems. humans might extract more water from the ground. human behavior does not change because of the water cycle. i'll be grateful if anyone can answer these 2 questions !

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.

Wave functions describe orbitals in a hydrogen atom. each function is characterized by 3 quantum numbers: n, l, and ml. if the value of n = 2: the quantum number l can have values from to . the total number of orbitals possible at the n = 2 energy level is .