An old movie poster used a quote "in space, no one can hear you scream! " why this is true or not true? a) the quote is incorrect, you can hear sound in outer space. b) sound cannot be polarized. so, you cannot hear sound in space. c) sound is an electromagnetic wave and needs no medium to travel through. eliminate d) sound needs a medium for the wave to vibrate and there is nothing in space to vibrate

D) Sound needs a medium for the wave to vibrate and there is nothing in space to vibrate

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation:

heat or electricity in the atmosphere- c.