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.
Answer:
Gliding
Explanation:
occurs when two bones slide across one another, such as in the intercarpal joints.
Answer:
Since sea urchins are picky, they are used as indicator organisms in public aquariums to determine if the system is functioning properly. This is because they are very "picky" about water quality. If the water is contaminated, the sea urchins will be the first to show signs of stress, spines laying down or falling off. Do use an aquarium filter and do clean up the day after feeding. Any metal exposed to the seawater will corrode and poison the tank. A dying sea urchin will often spawn out and rot out, causing the others in the tank to spawn and die as welll.
Explanation:
The geologic features that help scientists to determine the relative ages of rocks by their positions include index fossils, intrusions, and cross-cutting relationships (Option d).
<h3>What does geological age mean?</h3>
The expression geological age refers to the relative age of a given rock and or fossil (i.e. a piece or trace of dead organism) in a geological time scale.
In conclusion, the geologic features that help scientists to determine the relative ages of rocks by their positions include index fossils, intrusions, and cross-cutting relationships (Option d).
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