Board Thread:Questions and Answers/@comment-90.244.94.220-20141004224535/@comment-4621372-20141008025415

That's flat out impossible.

Earth's gravity cannot hold in Helium. That would escape to space.

Ditto the hydrogen.

CO2 and O2 are fine.

Sulfur Monoxide, bit weird, but wouldn't effect MUCH.

Argon, Ozone, Neon, Water Vapor, Sulfur Dioxide; pretty close to actual.

Chlorine? That's actually quite dangerous. 1 ppm is the advised cap for what you should be breathing, not 5000 ppm.

Free Oxygen. F*ck me. I can't even.

Nitrogen, would create issues with the plant life and bacteria, cause major cascade, kill a lot of things, but we'd not really notice them, even if we WEREN'T all dead from the Chlorine, Free Oxygen, and the sudden drop in pressure of over 1/3.

Yeah, Earth's dead.