A nucleoside has no natural group and is not a part of a nucleic acid.
Answer:
Which one? 1, 2, 3, 4 ,5, 6, or 7?
Explanation:
Answer:
MgO + H₂
Explanation:
The products of reaction is MgO and hydrogen gas.
This is a single displacement reaction.
In this reaction, the possibility of the reaction is determined by position of the atoms on the activity series.
Mg is higher than H on the activity series, so it is more reactive and it then displaces the hydrogen in water;
Mg + H₂O → MgO + H₂
Answer:- 
Explanations:- Let's say the first molecule is A and the second molecule is B and the product molecule is C.
From given information, 2 molecules of A react with 3 molecules of B to produce 5 molecules of C.
We write the reactants on left side and the product on right side and there is an arrow between them from reactants towards the products.
So, the reaction could be represented as:

They are about 4.5 billion years old. Hope this helps.