What is the minimum number of weights which enable us to weigh any integer number of grams of gold from 1 to 100 on a standard balance with two pans? (Weights can be placed only on the left pan)

For this type of question we have look that the number given comes between which two squares of $2$

Here, $100$ is given which come between $64$ and $128$ i.e. in between $2^6$ and $2^7$

So, we will take the lower square i.e. $6$ so the weights will be $6+1=7$

And, the weights will be $2^0, 2^1, 2^2, 2^3, 2^4, 2^5 \text{ and } 2^6$