Which of the following does not affect the apparent brightness of a star.
a) how old the star is
b) how big the star is
c) how hot the star is
d) how far away the star is

Which statement best explains why the overall charge on an atom is zero?

An alpha particle with kinetic energy 12.5 mev makes a collision with lead nucleus, but it is not "aimed" at the center of the lead nucleus, and has an initial nonzero angular momentum (with respect to the stationary lead nucleus) of magnitude l = p0 b, where p0 is the magnitude of the initial momentum of the alpha particle and b=1.40×10−12 m. (assume that the lead nucleus remains stationary and that it may be treated as a point charge. the atomic number of lead is 82. the alpha particle is a helium nucleus, with atomic number 2.) what is the distance of closest approach?

You notice the birds sitting on the electrical wires which of the following explain why the birds don't get shocked