Guys I need help with these questions 1. Define orbit:
2. What is the geocentric model?
3. What is the heliocentric model?
4. What is a star? What star is in our solar system?
5. Name two ways the planets in our solar system stay in orbit?

1.orbit is a regular, repeating path that one object in space takes around another one. An object in an orbit is called a satellite. A satellite can be natural, like Earth or the moon. Many planets have moons that orbit them.

2.the geocentric model is a superseded description of the Universe with Earth at the center. Under the geocentric model, the Sun, Moon, stars, and planets all orbited Earth.

3.Heliocentrism is the astronomical model in which the Earth and planets revolve around the Sun at the center of the Universe. Historically, heliocentrism was opposed to geocentrism, which placed the Earth at the

center.

4.The Sun is the Solar System's star and by far its most massive component. Its large mass (332,900 Earth masses), which comprises 99.86% of all the mass in the Solar System, produces temperatures and densities in its core high enough to sustain nuclear fusion of hydrogen into helium, making it a main-sequence star.

5.Newton concluded that two factors—inertia and gravity– combine to keep Earth in orbit around the sun, and the moon in orbit around Earth.

what is the volume occupied by 40 grams of argon gas (ar) at standard conditions? what volume, in liters, is occupied by 1.5 x 1023