Question

1. Which example below would not be found on primitive Earth?

volcanoes
lightning storms
oxygen gas
ammonia gas

2. Which event would have occurred by the end of the Hadean era?

Asteroid and comet bombardment had increased.
Earth’s crust had cooled and solidified
Lightning storms had stopped completely.
Free oxygen was available in the atmosphere.

3.
Classify Earth’s current atmosphere.

secondary atmosphere
quaternary atmosphere
primary atmosphere
tertiary atmosphere

Answer 1

1. oxygen gas

2. Asteroid and comet bombardment had

increased

3. A secondary atmosphere is an atmosphere of a planet that did not form by accretion during the formation of the planet's star. A secondary atmosphere instead forms from internal volcanic activity, or by accumulation of material from comet impacts.

The climate of the Quaternary period showed several decreases in global temperature (glacial periods) separated by warm (interglacial) periods. Core samples taken from sea beds elude to at least sixteen glaciations during the Quaternary period.

A primary atmosphere is an atmosphere of a planet that forms by accretion of gaseous matter from the accretion disc of the planet's sun. Planets such as Jupiter and Saturn have primary atmospheres. Primary atmospheres are very thick compared to secondary atmospheres like the one found on Earth.

Now we have Earth's “third atmosphere,” the one we all know and love—an atmosphere containing enough oxygen for animals, including ourselves, to evolve. So plants and some bacteria use carbon dioxide and give off oxygen, and animals use oxygen and give off carbon-dioxide—how convenient!