The arranged one in the decreasing order of thermal conductivity is

Options

A. copper, water, air
B. air, water, copper
C. air, copper, water
D. copper, air, water

Answer

To arrange the substances copper, water, and air in decreasing order of thermal conductivity, we follow these steps:

### Step 1: Identify the thermal conductivity values
- **Copper (Cu)**: The thermal conductivity is approximately **400 W/m·K**.
- **Water**: The thermal conductivity is approximately **0.598 W/m·K**.
- **Air**: The thermal conductivity is approximately **0.025 W/m·K**.

### Step 2: Compare the thermal conductivity values
Now, we compare the thermal conductivity values we have:
- Copper: **400 W/m·K**
- Water: **0.598 W/m·K**
- Air: **0.025 W/m·K**

### Step 3: Arrange in decreasing order
From the values, we can see that:
1. **Copper** has the highest thermal conductivity.
2. **Water** comes next.
3. **Air** has the lowest thermal conductivity.

Thus, the decreasing order of thermal conductivity is:
**Copper > Water > Air**

### Final Answer
The arranged order in decreasing thermal conductivity is:
**Copper, Water, Air**