`{:(1.,"Chemical symbol of potassium","(a)","Ca"),(2.,"Chemical symbol of calcium","(b)","Cu"),(3.,"Element with valency 4","(c)",Cu^(+)),(4.,"Element with variable valencies","(d)","K"),(5.,"Cation","(e)","C"):}`

Answer

To solve the matching type question, we need to match the items in the first column with the correct options in the second column based on the chemical symbols and properties of the elements. Let's go through each item step by step.

### Step 1: Identify the Chemical Symbol of Potassium
- The chemical symbol for potassium is **K**. This is derived from the Latin word "calium."
- **Match:** Potassium (1) matches with (d) K.

### Step 2: Identify the Chemical Symbol of Calcium
- The chemical symbol for calcium is **Ca**. This is a straightforward representation of the element's name.
- **Match:** Calcium (2) matches with (a) Ca.

### Step 3: Identify the Element with Valency 4
- The element with a valency of 4 is **Carbon**. In the compound methane (CH₄), carbon combines with four hydrogen atoms, indicating its valency.
- **Match:** Element with valency 4 (3) matches with (e) C.

### Step 4: Identify the Element with Variable Valencies
- The element that shows variable valencies is **Copper**. Copper can have a valency of +1 or +2, which makes it a transition metal with variable valencies.
- **Match:** Element with variable valencies (4) matches with (b) Cu.

### Step 5: Identify the Cation
- A cation is a positively charged ion. Among the given options, **Cu⁺** is the only cation, while the others are neutral.
- **Match:** Cation (5) matches with (c) Cu⁺.

### Final Matching
Now, let's summarize the matches:
1. Potassium - (d) K
2. Calcium - (a) Ca
3. Element with valency 4 - (e) C
4. Element with variable valencies - (b) Cu
5. Cation - (c) Cu⁺

Thus, the final answer is:
1. (d) K
2. (a) Ca
3. (e) C
4. (b) Cu
5. (c) Cu⁺