Elements [or radicals] with valency one are monovalent, those with valency two are divalent, and those with valency three are trivalent.
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What is the Valency of an Element / Radical?
Valency Divalent [2]
Element / Radical Oxide [Oxygen]
Symbol O
Ion O2-
1. without the atmosphere we would be freezing to detah
2. The atmosphere also protects us living things on Earth from the sun's harmful ultraviolet radiation
3.It also protects us from objects coming towards us from the sky such as a meteorite
4. It also provides oxygen for humans and animals so that we can breathe and also carbon dioxide for plants
I hope this helps!
Natural selection<span> is one of the basic mechanisms of evolution, along with mutation, migration, and genetic drift. </span>Results of these processes is the survival and reproduction of organisms which is best suited for their current environment. Hope this answers the question.
Then the species would either go extinct if it is a drastic change, or they would adapt to their surroundings, and pass on their adaptations to their offspring. Survival of the Fittest.
