Circle the correct answer 1. What is the basic building block for all matter in the universe? a. Cell b. Electron c. Nucleus d. Atom 2. What is a substance called that consists of a single type of atom? a. Element b. Compound c. Proton d. Molecule 3. What two basic particles make up the nucleus of an atom? a. Proton and Electron b. Neutrino and Neutron c. Neutron and Proton d. Electron and Quark 4. What positively charged particle is located at the center of the atom in the nucleus? a. Electron b. Proton c. Neutron d. Quark 5. What particle has no charge and affects the mass of the atom? a. Electron b. Proton c. Neutron d. Quark