Which statements describe the death of stars? Check all that apply.
A. Astar's final stages of life depend on its mass.
Stars die when they run out of fuel.
B. When a star starts to die, its core expands.
C. The outer portion of the star contracts.
D. All stars become black holes when they die.

Asample of silver (with work function ? = 4.52 ev) is exposed to an ultraviolet light source (? = 200 nm), which results in the ejection of photoelectrons. what changes will be observed if: silver is replaced with copper (? = 5.10 ev) more photoelectrons ejected no photoelectrons are emitted fewer photoelectrons ejected more energetic photoelectrons (on average) less energetic photoelectrons (on average)

Explain that newton first law, second law and third law of motion?

Consider the directing effects of the substituents on salicylamide and predict the possible structures of the iodination products. which do you think will be the major product?