ZulStrait

How do I tell whether in a chemical reaction, whether there has been a decrease in entropy? (More ordered)? Other than change of state from gas to liquid to solid?

Which of the following statements about thermal radiation is always true?

A. A cold object produces more total infrared and radio emission per unit surface area than a hot object.

B. A hot object produces more total infrared emission than a cooler object.

C. All the light emitted by hot object has higher energy than the light emitted by a cooler object.

D. A hot object emits more radiation per unit surface area than a cool object.

The official answer is C, which corresponds to Stefan-Boltzmann law, but isn't C correct too according to Wien's law? The answer says it's not correct though. Any explanations?

Hi, can someone offer me a simple explanation of the terms faults, slippages and breaks? in the context of an earthquake? Thanks.

Suppose that a lone asteroid happens to be passing Jupiter on an unbound orbit that keeps it well above Jupiter's atmosphere and far from all of Jupiter's moons. Which of the following statements would be true?

A. There is no way to predict what would happen.

B. Jupiter's gravity would capture the asteroid, making it a new moon of Jupiter.

C. Jupiter's gravity would suck in the asteroid, causing it to crash into Jupiter.

D. The asteroid's orbit around Jupiter would not change, and it would go out on the same unbound orbit that it came in on.

I know the answer is D. Can someone offer me an explanation as to why this is? I thought it was B

I understand that ammonia NH3 has 4 sp3 orbitals (one lone pair and 3 bond pairs with hydrogen) giving it a sp3-s-sigma bond with hydrogen. My question is, why is there a need for this hybrid when the hydrogen can just form s-p-sigma bonds with the 3 half filled p orbitals? Same goes for water H2O. I'm confused since a Cl2 molecule has a p-p sigma bond and not a sp3-sp3-sigma bond. Why the difference?