The equation $\backslash (\backslash$lambda f$=$c $\backslash )$ means $*(1$ Point$)$

that light travels at different speeds depending on its frequency.

that gamma rays, which have very large frequencies, have very small wavelengths and travel at the same speed as radio waves.

that light travels at different speeds depending on its wavelength.

that gamma rays, which have very large frequencies, also have very large wavelengths and travel faster than radio waves.

$30$

The most abundant elements in the universe today $*$

$(4)(1$ Point$)$

are hydrogen and helium, since they were produced only in the cores of stars.

are hydrogen and helium, since they do not exist in stars.

are hydrogen and helium, since they were most predominantly produced in the early universe.

are metals, since these are produced only in the cores of stars.