I do believe all of these but core elements can be determined by spectroscopy which includes the use of electromagnetic radiation. Both the surface and core temperature can be measured using light. Surface elements can be found because the absorption lines of different elements in the spectra of the star, but I haven't heard anything about using spectral analysis for core elements.
Answer: Wave speed= frequency x wavelength
=20 x 3
=60 m/s
Explanation:
A cloud in space that is composed of dust and gas is call a nebula. The word "nebula" is derived from the Latin word for "cloud," and nebulae in space are indeed large interstellar clouds made up of dust, hydrogen, helium and plasma.
Answer:
<h2>2.4</h2>
Explanation:
<h2><em>Hope it help mark as Brainlist</em></h2>