The gold number of four colloids A, B, C and D are 0.005, 0.08, 25 and 0.10 respectively. Their protective power has the order:

Options

A. `A gt B gt C gt D`
B. `A gt B gt D gt C`
C. `D gt C gt B gt A`
D. `C gt D gt B gt A `

Answer

To determine the protective power of the colloids A, B, C, and D based on their gold numbers, we can follow these steps:

### Step 1: Understand Gold Number
The gold number is a measure of the protective power of a colloid. It indicates the minimum amount of a lyophilic colloid required to prevent the precipitation of a lyophobic colloid. A lower gold number indicates a higher protective power.

### Step 2: List the Gold Numbers
We have the following gold numbers for the colloids:
- Colloid A: 0.005
- Colloid B: 0.08
- Colloid C: 25
- Colloid D: 0.10

### Step 3: Compare Gold Numbers
To determine the protective power, we need to compare the gold numbers. The order of protective power is inversely related to the gold number. Thus, we will arrange the colloids from the lowest to the highest gold number.

### Step 4: Arrange in Order of Protective Power
- Colloid A (0.005) has the lowest gold number, indicating it has the highest protective power.
- Colloid B (0.08) is next, so it has the second highest protective power.
- Colloid D (0.10) follows B.
- Colloid C (25) has the highest gold number, indicating it has the lowest protective power.

### Conclusion
The order of protective power from highest to lowest is:
1. A (0.005)
2. B (0.08)
3. D (0.10)
4. C (25)

### Final Answer
The protective power has the order: A > B > D > C.

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