Answer: changed by molecular oxygen
Explanation:
Biologically induced molecular oxygen (dioxygen, O2) started to accumulate in Earth's atmosphere and changed Earth's atmosphere from a weakly reducing atmosphere to an oxidizing atmosphere.
Answer:
C. Atoms lose energy as a gas changes to a solid.
Explanation:
Physical changes of matter take place by adding or removing energy from the matter.
In the given images, The<em> left cylindrical is showing gas phase while the right cylindrical is showing a solid phase.</em>
The process of conversion of gas into solid is called deposition. Deposition process takes place when atoms lose their energy and have high kinetic energy so they directly convert into solid and not into liquid.
Hence, the correct option is "C".
Answer:
Sewage treatment generally involves three stages, called primary, secondary and tertiary treatment. Primary treatment consists of temporarily holding the sewage in a quiescent basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface.
Explanation:
Hope that helps:)
Answer:
To reduce water loss.
Explanation:
Keeping the stomata closed during the day, helps reduce water loss when dry, hot wind blows across it.