Question

protons are positively charged and repel other protons. which other particle is found in the nucleus and separates protons so that the strong force can hold the nucleus together? a electrons b neutrons c protons d quarks

Explanation:

Electrons are outside the nucleus, so A is wrong. Protons are the ones that need separation, so C is wrong. Quarks are part of protons and neutrons but not the particle that separates protons in the nucleus. Neutrons are neutral - charged particles in the nucleus. They can separate protons, allowing the strong nuclear force (which acts over short distances) to hold the nucleus together despite the electrostatic repulsion between protons.

Answer:

B. neutrons