Earth's History, Trees, and Atmosphere

Earth's current atmosphere is

• 78% nitrogen, 21% oxygen, 0.9% argon and 0.037% carbon dioxide
• 78% oxygen, 21%nitrogen, 0.9% argon, 0.037% carbon dioxide
• 78% nitrogen, 21% argon, 1% oxygen
• 78% oxygen, 21% nitrogen, 1% carbon dioxide

The layers of the atmosphere in order from bottom to top are

• troposphere, stratosphere, mesosphere, thermosphere, exosphere
• troposphere, mesosphere, atmosphere, thermosphere
• mesosphere, thermosphere, troposphere, stratosphere, exosphere
• thermosphere, stratosphere, mesosphere, troposphere, exosphere

The layer of the atmosphere containing the ozone layer is

• troposphere
• stratosphere
• thermosphere
• mesosphere

The layer of the atmosphere containing our weather is

• thermosphere
• stratosphere
• troposphere
• mesosphere

The Precambrian is the ___________ time span in Earth's history.

• youngest
• latest
• earliest
• middle

Current scientific evidence shows that the Earth is estimated to be: 

• Less than 1 millions years old
• Between 3 and 4 billion years old
• More than 4 billions years old
• Less than 2 billion years old

What is absolute age?

• comparing a rock layer to other rocks

• a measure of the radioactive decay of isotopes

• measuring the dimensions of a rock

• comparing the rocks to the fossils in the area

The layer of the atmosphere where meteors burn up _?_.

• mesosphere
• thermosphere
• troposphere
• stratosphere

The layers of the atmosphere that get hotter with increased altitude are the _?_.

• thermosphere and mesosphere
• troposphere and mesosphere
• thermosphere and stratosphere
• stratosphere and mesosphere

The layers of the atmosphere that get colder as altitude increases are _?_.

• thermosphere and troposphere
• mesosphere and troposphere
• stratosphere and thermosphere
• thermosphere and mesosphere