Chapter 52 · 824 practice MCQs
MDCAT Nuclear Physics MCQs 2026 | Half-Life & Decay
A nucleus keeps its own clock. Unit 16 is composition, random spontaneous decay, = 0.693/ , and medical radiation — heating the sample does not hurry it.
·6 min read·Usman Ubaid
What MDCAT 2026 asks in Unit 52 Nuclear Physics
PMDC 16.1–16.4 is the nuclear slice MDCAT actually names: who lives in the nucleus, that decay is random and spontaneous, half-life, and biological/medical uses. This quiz does not wander into binding-energy tables or reactor engineering that the outcome list does not ask.
Protons and neutrons in a tiny nucleus, electrons outside. + N. Charge +Ze. Isotopes share Z, differ in N. Decay is random (which nucleus, when) and spontaneous (T, P and chemistry do not set ). is ⁴He (A−4, Z−2). ⁻ is n→p (A same, Z+1). leaves A and Z still.
After n half-lives, (1/2)ⁿ remains. Activity with = 0.693/ . does not care how big the pile is. Tracers are (they leave the body and hit a camera). is stopped by paper and is a hazard if swallowed. Sterilising a pack with radiation does not make the pack a source. Twenty labs.
- + N. Isotopes: same Z, different N. Charge +Ze.
- Random and spontaneous — T, P, chemical state do not set .
- (1/2)^n after n half-lives. = 0.693/ .
- Activity Bigger pile, bigger activity, same .
- Tracers vs therapy vs sterilisation — pick the radiation that matches the job.
Often-asked Nuclear Physics MCQ patterns
These are the Nuclear Physics ideas that keep coming every year with new numbers.
- Heating a sample to speed decay.
- 1/3 remaining after three half-lives (it is 1/8).
- as a tracer that ‘lights up’ a camera ( does).
- A sterilised pack becoming a long-lived source.
- / 0.693, upside down.
- Electrons inside the nucleus.
Worked Nuclear Physics numericals (
Work these on paper first. Then open the Unit 52 quiz — the same numbers are in the questions, with wrong options built from the usual mix-ups.
A sample has = 2 h. Fraction remaining after 6 h?
- = 3 half-lives.
- 1/3 is the trap that treats half-life as a third.
1/8 remains. Activity is also 1/8 of the original, same clock.
Parent ²³⁸U ( emits an . Daughter?
- is ⁴He, so A → 234, Z → 90 (thorium).
- ⁻ would have kept and made
²³⁴Th. Count A and Z; do not guess the name first.
Nuclear Physics traps that steal the mark
A good option is a true sentence about the wrong quantity. If you miss, the quiz names the mix-up on the option you actually picked.
- Heating a sample to speed decay.
- 1/3 remaining after three half-lives.
- as a tracer that ‘lights up’ a camera.
- A sterilised pack becoming a long-lived source.
- Putting electrons in the nucleus.
- Saying is shorter for a larger sample.
Nuclear Physics formula sheet for MDCAT 2026
Write these until they are cheaper than thinking. Then open the Nuclear Physics quiz and make the picture agree.
How to practise Unit 52 Nuclear Physics MCQs
On decay equations, write A and Z as a two-column check before you name the particle.
On half-life, count doublings of time, not thirds of sample. Sketch the staircase: 1 → ½ → ¼ → ⅛.
Sit Nuclear last. It shares ‘random’ with nothing else, and it shares only when a is a photon — that was Unit 14.
Choose topics and a test length up to 180 from the 824-question bank. Tutor Mode explains each selection; Timed Exam reveals explanations on submission. Use the complete review to revise mistakes and download your results.
FAQ
Common questions
Does half-life depend on the amount of sample?
No. A bigger pile has a bigger activity, but both piles hit 50% at the same . Activity depends on the number of undecayed nuclei, whereas = ln2/ is a property of the radionuclide. Doubling the sample doubles initial activity but does not double half-life.
Can you speed radioactive decay by heating?
No. Decay is spontaneous. Temperature, pressure and chemical state do not set in MDCAT. Ordinary temperature and pressure changes do not appreciably alter the nuclear decay rates considered in these MDCAT questions. Do not confuse nuclear decay with chemical reaction rates.
Which radiation is used as a medical tracer?
Gamma. It leaves the body and is seen by a camera. Alpha is stopped by paper and is the wrong tool for imaging. Imaging needs radiation that can escape the body and reach a detector, often gamma rays. The selected radionuclide should also have suitable half-life and biological uptake; therapeutic sources have different requirements.
What remains after three half-lives?
One eighth, (1/2)³. Not one third. The remaining fraction after n half-lives is (1/2)ⁿ. After three half-lives, 12.5% remains and 87.5% has decayed; distinguish remaining fraction from decayed fraction.
How many Nuclear Physics MCQs are available on DIFF. MDCAT?
The current Nuclear Physics question bank contains 824 practice MCQs across 4 topics. This is the bank size, not the length of one test. Choose your topics and a question count from 1 to 180, limited by the questions available in those topics.
Which topics does the Nuclear Physics quiz cover?
The selectable topics are Nuclear Structure, Radioactive Decay, Half-Life, Radiation Uses. Use Select all for a broad chapter drill, Clear to start a focused selection, or choose individual topics. Questions are drawn from your chosen topics, so you can target a weak concept before returning to a wider test.
How do I build a custom Nuclear Physics test?
Open the chapter builder, select one or more topics, enter your question count, and choose Tutor Mode or Timed Exam. The available-question total updates with your selection. Start Test generates a shuffled drill; you do not have to follow a fixed Quiz 1 or Quiz 2 sequence.
What is the difference between Tutor Mode and Timed Exam?
Tutor Mode gives feedback and an explanation after you choose an option, and you can change or clear that choice. Timed Exam runs a countdown and keeps explanations hidden until submission. Both modes let you move between questions, use the paper map, and submit for a complete review.
How do I review and download my Nuclear Physics quiz?
Select Submit Quiz, then Submit & View Explanations. The review includes every question in your test, all options, your selection, the marked correct answer when a key is available, and the explanation. Download PDF saves a paginated review; Download Review saves an HTML copy you can open in a browser. The review also includes DIFF. MDCAT community links.
How should I use Nuclear Physics MCQs to improve?
Start with a short tutor drill on one of these topics: Nuclear Structure, Radioactive Decay, Half-Life. Read the explanation for incorrect and uncertain answers, revise the relevant textbook section, and retry before taking a timed drill. Compare your reasoning with the answer key rather than memorising the option letter.
Ready to sit Unit 52 Nuclear Physics — 824 MCQs, 824 labs?