Stars & Planets - Introduction - 1) General Knowledge on Stars

 Which is the most abundant element in the Universe ?
 Where/How was Helium first discovered ?
 All the elements where produced during the Big Bang.
 Why do stars shine ?
 What is roughly the temperature at the center of the Sun ?
 Massive stars live longer than low-mass stars.
 What is the approximate lifetime of the Sun ?
 The Sun will end its life as a
 A type Ia Supernovae is the explosion of
 Betelgeuse is a
 Where is/was Hydrogen produced?
 Lead (Pb) is produced by
 Which are the most numerous stars
 Who discovered the Pulsars?
 Which of these can be used as standard candles to measure extra-galactic distances?
 According to Planck's law, the spectral distribution of a thermal energy radiated by a black body (i.e. the pattern of the intensity of the radiation over a range of wavelengths or frequencies) depends
 The Hertzprung-Russel diagram shows
 What is the so-called Kelvin-Helmoltz timescale for stars?