Protons and neutrons are made from which of the following particles?

up quarks only
up quarks and down quarks <my choice
down quarks only
hadrons

That is correct.

See your other post above.

To determine which particles make up protons and neutrons, we need to understand the composition of these particles. Protons and neutrons are examples of hadrons, which are composite particles made up of more fundamental particles called quarks.

Quarks are elementary particles that come in six different types or flavors: up, down, charm, strange, top, and bottom. Protons consist of three quarks, while neutrons are also made up of three quarks.

The possible quark combinations for forming protons and neutrons are as follows:
- Proton: Two up quarks and one down quark (uud)
- Neutron: One up quark and two down quarks (udd)

Given the choices, protons and neutrons are made up of up quarks and down quarks. Therefore, the correct answer is "up quarks and down quarks".