Answer:
Radon 222.
Explanation:
This is a chemically inert gas that is colourless and odourless but it is radioactive. It is produced by uranium in rock. From seeping through foundation, its accumulation can cause lung cancer. Also, as a radioactive gas, it can be also used to in hospitals to cure ailments which includes tumour , cancer and other diseases.
Green plants use their chlorophyll to capture the energy of sunlight and split water molecules. As they do, they release oxygen into the air. Green plants use energy from the sunlight and carbon dioxide from the air to make sugar. In effect, they create “mass” from “gas.”
Answer:
The atmospheric pressure goes on decreasing as we go up above the sea-level. Therefore, the amount of oxygen also decreases at higher altitude. Due to this reason, mountaineers carry oxygen cylinders with them, while climbing high mountains
Explanation:
Answer:
The preferable statement will be - D.
D. They show a transitional form between fish and land-dwelling vertebrates.
Explanation:
From the given information we know that the fossil of that type of animal has scales, fins, gills, lungs, a full set of ribs, and limb bones.
This indicates some things such as,
- There is a high chance that the animal was capable of living in both land surface and water.
- Scales, fins, and gills indicate that they were like fish or water vertebrates.
- But lungs, a full set of ribs, and limb indicates that they are showing a transitional form between water and land-vertebrates.
