The given reaction above is an example of <em>**single replacement reaction. **</em>This is a certain type of reaction in which an element of a compound is replaced by a free element. In this case, chlorine (Cl) is replaced by calcium (Ca).

**Answer:**

Minimum number of lines, N = 3690.64

**Explanation:**

Mean of wavelengths,

Smallest resolvable wavelength difference,

**Resolution of diffraction grating is given by :**

For first order, m = 1

**N is the minimum number of lines**

**N = 3690.64**

**Hence, the minimum number of lines needed in a diffraction grating that can resolve these lines in the first order is 3690.64. Hence, this is required solution.**

**Answer:**

Air and water i think

**Explanation:**

Cause Air =25% and water=25% so that equals 50%