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:
oxygen is an element and water is a compound
Explanation:
oxygen is made up of two atoms and water is made up of two elements
The first step begins with: A. the mouth.
Answer:
a
Explanation:
According to the taxonomical hierarchy, the kingdom is the highest category in biological classification. It is a group of closely related organisms.
Kingdom - Phylum -Class - Order -Family - Genus -Species.
