Answer:
Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum. The word usually refers to visible light, which is the visible spectrum that is visible to the human eye and is responsible for the sense of sight.
Answer:
The correct answer will be-gas absent in primordial atmosphere (oxygen).
Explanation:
The Miller experiment was performed in 1953 to show that organic molecules can be formed from the inorganic molecules in the conditions resembling the primordial atmosphere.
Same conditions were created to the unstable atmosphere like a mixture of gases which included- methane, sulfur dioxide and hydrogen but lacked oxygen as it was absent in the primordial atmosphere.
Thus, gas absent in the primordial atmosphere (oxygen) is the correct answer.
In groups such as, igneous, sedimentary, or metamorphic
Hard water contains mineral ions basically the calcium and magnesium ions.
The presence of hard water often considered a negative thing as it is associated with a number of issues related to plumbing, water storage as well as cleaning and maintenance.
Hard water leads to clogged pipes due to the deposition of ions on the surface of water conducting pipes. This hindrance also degrades the quality of equipment used for water storage and heating e.g. geysers.
The hardness of water can either be temporary or permanent depending on the type of ions present in it. Temporary hard water contains calcium and magnesium ions whereas Permanent hard water contains anions like the sulfate ion.
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