I am John. I always get up late at the weekend. At about 9:30 am, I have breakfast. After breakfast, I start doing my homework. We have lunch at about 12:00, and then I watch TV or have a rest. I like reading and I often read some interesting books in the afternoon. I like sports, too. Sometimes I play football or basketball with my friends at school. My school is near my home, so I can walk there. Every weekend, my father takes me to a restaurant for a big dinner. I can enjoy lots of nice food. I like my weekend.

把10g铁粉与铜粉的混合物放到盛有足量稀硫酸的烧杯中，充分反应后，烧杯中物质的总质量比反应前金属混合物与稀硫酸的总质量减少了0.1g，求混合物中铁的质量分数．

某校七年级（1）班以此为背景，召开了一次以“青春的活力、青春的奋斗”为主题的班会活动。请你参与活动并完成相关任务。