Set up the problem with the conversion rates as fractions where when you multiply the units cancel out leaving the desired units behind.
Answer:

Explanation:
-The chemical formula for Molybdenum (V) Dichromate is 
-There are 21 moles of oxygen per one mole of Molybdenum (V) Dichromate
-We apply Avogadro's constant to find the number of atoms of oxygen:

Hence, there are
Answer:
orbit the sun have very elliptical orbits
are made of frozen gas and ice
Explanation:
Comets are the made up of dry ice, frozen water, gases and dust particles. it is called dirty snow balls as their nucleus carry frozen water and pieces of rock.
Comets move around the sun in an elliptical orbits and follow Kepler's Laws saying that they move faster when closer to the Sun.
Comets have tails even when they are far from the sun and the tails that point away from the sun.
Hence, the correct options are "orbit the sun have very elliptical orbits and are made of frozen gas and ice".
Answer:
It's only 1.11 m/s2 weaker at 400 km above surface of Earth
Explanation:
Let Earth radius be 6371 km, or 6371000 m. At 400km above the Earth surface would be 6371 + 400 = 6771 km, or 6771000 m
We can use Newton's gravitational law to calculate difference in gravitational acceleration between point A (Earth surface) and point B (400km above Earth surface):

where G is the gravitational constant, M is the mass of Earth and r is the distance form the center of Earth to the object





So the gravitational acceleration at 400km above surface is only 0.885 the gravitational energy at the surface, or 0.885*9.81 = 8.7 m/s2, a difference of (9.81 - 8.7) = 1.11 m/s2.
Increase in velocity and decrease in velocity are the answers
Because acceleration is just the change if it starts moving