`{:(,"Column-I",,"Column-II",),((A),"Cathode rays",(p),"Helium nuclei",),((B),"dumb-bell",(q),"Uncertainty principle",),((C),"Alpha particles",(r),"Electromagnetic radiation" ,),((D),"Moseley",(s),"p-orbital",),((E),"Heisenberg",(t),"Atomic number",),((F),"X-ray",(u),"electrons",):}`

Answer

To solve the matching question between Column-I and Column-II, we will analyze each item in Column-I and find its corresponding match in Column-II based on our understanding of chemistry concepts.

### Step-by-Step Solution:

1. **Match A: Cathode rays**
- Cathode rays are streams of electrons, which are negatively charged particles.
- **Match:** A (Cathode rays) → U (electrons)

2. **Match B: Dumb-bell**
- The term "dumb-bell" refers to the shape of the p-orbital in atomic structure.
- **Match:** B (dumb-bell) → S (p-orbital)

3. **Match C: Alpha particles**
- Alpha particles are positively charged particles that are essentially the nucleus of a helium atom (two protons and two neutrons).
- **Match:** C (Alpha particles) → P (Helium nuclei)

4. **Match D: Moseley**
- Moseley was an English physicist who established the concept of atomic number and arranged elements in the periodic table according to atomic number rather than atomic mass.
- **Match:** D (Moseley) → T (Atomic number)

5. **Match E: Heisenberg**
- Heisenberg is known for the Uncertainty Principle, which states that one cannot simultaneously know the exact position and momentum of a particle.
- **Match:** E (Heisenberg) → Q (Uncertainty principle)

6. **Match F: X-ray**
- X-rays are a form of electromagnetic radiation.
- **Match:** F (X-ray) → R (Electromagnetic radiation)

### Final Matches:
- A → U (Cathode rays → electrons)
- B → S (dumb-bell → p-orbital)
- C → P (Alpha particles → Helium nuclei)
- D → T (Moseley → Atomic number)
- E → Q (Heisenberg → Uncertainty principle)
- F → R (X-ray → Electromagnetic radiation)

### Summary of Matches:
- A - U
- B - S
- C - P
- D - T
- E - Q
- F - R