Approximate atomic weight of an element is 26.89. If its equivalent weight is 8.9, the exact atomic weight of element would be

The correct option is 26.7.

To find the exact atomic weight of the element, we first need to determine its valency. The relationship between atomic weight, equivalent weight, and valency is given by the formula:
$$\text{Valency}=\frac{\text{Approximate Atomic Weight}}{\text{Equivalent Weight}}$$

Substituting the given values into the formula:
$$\text{Valency}=\frac{26.89}{8.9}\approx 3.02$$

Since valency must be an integer, we round the calculated value of 3.02 to the nearest whole number. Therefore, the valency of the element is 3.

Now, we calculate the exact atomic weight using the relationship:
$$\text{Exact Atomic Weight}=\text{Equivalent Weight}\times \text{Valency}$$

Substituting the equivalent weight of 8.9 and the integer valency of 3:
$$\text{Exact Atomic Weight}=8.9\times 3=26.7$$

Thus, the exact atomic weight of the element is 26.7, which corresponds to the correct option.