The answer would be 5.6x10^5
During either one, the sun, moon, and Earth are lined up in the same straight line. The difference is whether the moon or the Earth is the one in the "middle".
At the present time, the only way we know of that light can get shifted
toward the blue end of the spectrum is the Doppler effect ... wavelengths
appear shorter than they should be when the source is moving toward us.
IF that's true in the case of the Andromeda galaxy, it means the galaxy is
moving toward us.
We use the same reasoning to conclude that all the galaxies whose light is red-shifted are moving away from us. That includes the vast majority of all galaxies that we can see, and it strongly supports the theory of the big bang
and the expanding universe.
If somebody ever comes along and discovers a DIFFERENT way that light
can get shifted to new, longer or shorter wavelengths, then pretty much all
of modern Cosmology will be out the window. There's a lot riding on the
Doppler effect !
Answer:
2 Mg(s) + O2(g) → 2 MgO(s)
As magnesium (Mg) has a valency of +2, and oxygen (O) has a valency of -2, the ratio would be 1:1, and magnesium oxide would be represented as MgO. It is insoluble in water, hence it has the subscript as a solid, represented by (s). In order to use up the diatomic oxygen (O2), there needs to be two moles of magnesium (2Mg) on the reactant side. This would produce 2 moles of MgO on the product side.
Explanation:
Average velocity is the change in distance divided by the time it takes to travel that distance. so the first one.
