Understanding the Concept

Dalton's Atomic Theory states that atoms of different elements combine in whole number ratios to form compounds. This means the ratio of elements in a compound is always consistent.

Applying the Theory

1. Ratio: We know that 2 grams of X combine with 4 grams of Y to form XY. This gives us a ratio of 2:4, which simplifies to 1:2. This means for every 1 gram of X, you need 2 grams of Y.

2. Scaling the Ratio: To make 28 grams of the compound, we need to figure out how much X and Y we need. Since the ratio is 1:2, we can divide the total mass (28 grams) into three equal parts: 28 grams / 3 = 9.33 grams per part.

3. Calculating the Mass of X and Y:

* X: 1 part * 9.33 grams/part = 9.33 grams

* Y: 2 parts * 9.33 grams/part = 18.66 grams

Answer

To make 28 grams of compound XY, you would need 9.33 grams of element X and 18.66 grams of element Y.