Physics Physics Nuclear Physics 1 โ Questions and Answers
Question 1: What particles make up the atomic nucleus?
- Protons and neutrons (Correct answer)
- Electrons and protons
- Electrons and neutrons
- Quarks and leptons only
Correct answer: Protons and neutrons
The atomic nucleus is composed of protons (positively charged) and neutrons (neutral), collectively called nucleons.
Question 2: The atomic number of an element equals the number of:
- Protons in the nucleus (Correct answer)
- Neutrons in the nucleus
- Total nucleons
- Electrons in the outer shell
Correct answer: Protons in the nucleus
The atomic number (Z) equals the number of protons in the nucleus and uniquely determines the chemical identity of an element.
Question 3: Isotopes of an element have the same number of protons but different numbers of:
- Neutrons (Correct answer)
- Electrons
- Protons
- Energy levels
Correct answer: Neutrons
Isotopes are atoms of the same element with the same atomic number but different numbers of neutrons, giving them different mass numbers.
Question 4: What force holds protons and neutrons together in the nucleus?
- Strong nuclear force (Correct answer)
- Electromagnetic force
- Gravitational force
- Weak nuclear force
Correct answer: Strong nuclear force
The strong nuclear force holds nucleons together in the nucleus, overcoming the electromagnetic repulsion between the positively charged protons.
Question 5: The mass number of an atom equals:
- Number of protons plus neutrons (Correct answer)
- Number of protons minus neutrons
- Number of electrons plus protons
- Atomic weight in grams per mole
Correct answer: Number of protons plus neutrons
The mass number (A) is the total count of nucleons โ protons plus neutrons โ in an atom's nucleus.
Question 6: What is nuclear binding energy?
- Energy needed to completely separate all nucleons in a nucleus (Correct answer)
- Energy released when an electron is added to an atom
- Energy required to ionize an atom completely
- Energy stored in covalent chemical bonds
Correct answer: Energy needed to completely separate all nucleons in a nucleus
Nuclear binding energy is the energy required to completely separate a nucleus into its individual protons and neutrons, equivalent to the mass defect via E = mcยฒ.
Physics Physics Nuclear Physics 1
What particles make up the atomic nucleus?