The correct option is C.
In chemistry, a radical is defined as an atom, ion or molecule that possess an unpaired valence electron. Generally, radicals are highly reactive chemically. Examples of radicals are hydroxyl, hypochlorite, nitrate, carbonate, oxalate, permanganate, etc. Free radicals combine with one another or with single atoms to produce neutral substances. In the question given above, the two compounds given in option C have the same type of radical, which is hydroxyl radical.
Mendeleev organized the chemical elements based on their properties.
Mendeleev put elements in order in the periodic table according to their physical and chemical properties. He noticed that properties of elements were related to their atomic mass in a 'periodic' way, so he groups of elements with similar properties into vertical columns in the table. His periodic table had initial 63 elements which then expanded to 108 or 109 elements.
i think they are called that, Mimicked genes
The answer is A. They contain a large amount of gas and dust
