What is Air

What does the term "atmosphere" literally mean?

• Layer of clouds

• Sphere of air

• Gaseous envelope

• Protective shield

What two elements were likely prevalent in Earth's early atmosphere but largely escaped due to heat and proximity to the Sun?

• Nitrogen and Oxygen

• Carbon Dioxide and Methane

• Hydrogen and Helium

• Water Vapor and Neon

Which organisms were primarily responsible for introducing significant amounts of oxygen into Earth's atmosphere through photosynthesis?

• Extremophiles

• Cyanobacteria

• Volcanoes

• Asteroids

What is the most abundant gas in Earth's current atmosphere?

• Oxygen

• Carbon Dioxide

• Nitrogen

• Argon