Boron
You start at He and work you way down
Post the answer choices please. So we can help you answer the question
Answer:
0.91 g NaF
Explanation:
Mass percentage is one way of representing the concentration of an element in a compound or a component in a mixture. Mass percentage is calculated as the mass of a component divided by the total mass of the mixture, multiplied by 100%.
Let mass of NaF = x g
∴ mass percent = mass of NaF / mass of total mixture *100
3.5 = (x/ x + 25) * 100
∴ x = 0.91 g
