Answer: (1) functional groups
Explanation:
Functional groups are specific group of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules.
The compounds having similar molecular formula but different arrangement of atoms or groups in space are called isomers and the phenomenon is called as isomerism.
Butanal is 
and butanone is 
.
and are functional isomers which have same molecular formula , similar masses and same number of carbon atoms per molecule but different functional groups attached.
Hey just say that the water carrys sediment to different places by it current if i put sand in a stream it will go down it
B. Representative electrons
Firstly it is best to describe the shape and structure of an atom, an atom's system and structure is like of the solar planet, the heliocentric view where the sun is the neutrons and protons and the planets are the electrons. Moreover, the electrons are outside these neutrons and protons surrounding the entire system of its atomic structure. Its movement is like of a planet.
<span>An energy level also known as electron shell, or just shell is a location around an atom where electrons with a specific energy value, or quantum number may be found.</span>
True, False , and I think the last one is true
