CSS - PMS - CCE - PCS - General Science
Atomic Structure - Protons
Why can multiple protons remain bound in a nucleus despite electrostatic repulsion?
A. Protons become electrically neutral in nuclei
B. Gravity dominates at nuclear scale
C. The strong nuclear force can overcome repulsion at very short distances
D. Electrons sit between every pair of protons
Correct Answer: C
The attractive strong nuclear interaction is dominant over very short nuclear distances.
CSS - PMS - CCE - PCS - General Science
Atomic Structure - Protons
Which force causes electrostatic repulsion between protons in a nucleus?
A. Friction
B. Electromagnetic force
C. Strong force only
D. Gravity only
Correct Answer: B
Like positive charges repel through the electromagnetic interaction.
CSS - PMS - CCE - PCS - General Science
Atomic Structure - Protons
Which particle is the nucleus of ordinary hydrogen and is also emitted in some nuclear reactions?
A. Proton
B. Photon
C. Electron
D. Neutrino
Correct Answer: A
A hydrogen-1 nucleus consists of one proton.
CSS - PMS - CCE - PCS - General Science
Atomic Structure - Protons
Which nucleus contains exactly one proton and no neutron?
A. Deuterium
B. Helium-4
C. Hydrogen-1
D. Carbon-12
Correct Answer: C
The protium nucleus is a single proton.
CSS - PMS - CCE - PCS - General Science
Atomic Structure - Protons
A neutral atom with 17 protons contains how many electrons?
A. 17
B. 18
C. 34
D. 16
Correct Answer: A
Electrical neutrality requires equal numbers of protons and electrons.
CSS - PMS - CCE - PCS - General Science
Atomic Structure - Protons
Approximately how much mass does a proton have in atomic mass units?
A. Exactly 0 u
B. About 1 u
C. About 0.0005 u
D. About 100 u
Correct Answer: B
A proton has a mass close to one unified atomic mass unit.
CSS - PMS - CCE - PCS - General Science
Atomic Structure - Protons
What happens to elemental identity when proton number changes?
A. Only electron charge changes
B. Only the isotope changes
C. The atom becomes a different element
D. Nothing changes
Correct Answer: C
Element identity is determined by atomic number, which equals proton number.
CSS - PMS - CCE - PCS - General Science
Atomic Structure - Protons
Which atomic quantity equals the number of protons?
A. Neutron number
B. Number of isotopes
C. Atomic number
D. Mass number always
Correct Answer: C
Atomic number Z is defined by proton count.
CSS - PMS - CCE - PCS - General Science
Atomic Structure - Protons
Where are protons located in an atom?
A. In electron shells
B. In the nucleus
C. Inside molecules but not atoms
D. Outside the atom only
Correct Answer: B
Protons are nucleons located in the atomic nucleus.
CSS - PMS - CCE - PCS - General Science
Atomic Structure - Protons
What is the electric charge of a proton?
A. Neutral
B. Positive
C. Negative
D. Variable only
Correct Answer: B
A proton carries one elementary unit of positive charge.