There is 40% of oxygen. If your mineral sample has a mass of 10g, how many grams of oxygen does it have. wouldn't it have 4 grams?

yes, exactly right.

Yes, you are correct. To determine the number of grams of oxygen in a mineral sample, you can use the given percentage of oxygen and the mass of the sample.

In this case, you have been given that there is 40% oxygen in the mineral sample, and the sample has a mass of 10g.

To calculate the grams of oxygen, you can use the following equation:

Grams of oxygen = (Percentage of oxygen / 100) * Mass of the sample

Substituting the given values, we have:

Grams of oxygen = (40 / 100) * 10g

Calculating further:

Grams of oxygen = 0.4 * 10g

Grams of oxygen = 4g

Therefore, the mineral sample contains 4 grams of oxygen.