Which is more common: a star blows up as a supernova, or a star forms a planetary nebula/white dwarf system?

1.what is where an object is located 2. what is how fast an objects speed is changing 3. what is how fast an object is moving

What do the atoms of elements in the same group have in common? a. they have the same atomic numbers. b. they have the same average atomic masses. c. they have the same number of electron shells. d. they have the same number of electrons in their outermost shells.

Which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?