Quarks are thought to be the building blocks of protons. which was most affected by the discovery of the quark?
a the estimated mass of a proton
b the observation that protons have a +1 charge
c the view that the atom cannot be broken down further than protons
d the theory that the nucleus of an atom contains protons and neutrons

C. the view that the atom cannot be broken down further than protons  

Explanation:

Atom is considered as the smallest unit of matter. An atom contains protons and neutrons in the nucleus and electrons orbiting the nucleus in fixed energy shells.

It was thought that atom cannot be broken down further than these particles until quarks were discovered. A proton contains three quarks- 2 up quarks and 1 down quark.

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