Answer: water (H2O): Water is an excellent example of hydrogen bonding. ...
chloroform (CHCl3): Hydrogen bonding occurs between hydrogen of one molecule and carbon of another molecule.
ammonia (NH3): Hydrogen bonds form between hydrogen of one molecule and nitrogen of another.
Explanation:
Answer:
D
Explanation:
The force of gravity depends directly upon the masses of the two objects, and inversely on the square of the distance between them. This means that the force of gravity increases with mass, but decreases with increasing distance between objects.
Cutting of Nails is a Physical Change since no new substance is formed.
Don't confuse it with Reversible and Irreversible Changes
Explanation:
Chemical formula of chalcone is 
and during the preparation of chalcones, a base like sodium hydroxide acts like a catalyst. This catalyst helps in the abstraction of proton from the methyl group acetophenone in order to obtain a negative charge methylene group.
This methylene group then attacks carbonyl carbon of the benzaldehyde.
