Chemistry

2. You can get me for free, but inside an atom, I add a lot of weight. What am I?
4. I am very important for building strong and healthy bones and teeth. You can find me in every dairy product. What am I?
6. If you mix me with Hydrogen, you’ll sense a nasty smell of rotten eggs. What am I?
8. I can keep a swimming pool clean, but I can poison you as well. What am I?
10. I'm unique in one way but you can find two of me in your daily drink. What am I?
11. Shiny like a silver, denser than lead, pricier than gold, could stop a bullet, if I wanted to. What am I?

1. What can eat a lot of iron without getting sick?
3. I am bigger than a dime but worthless. What am I?
5. I am a planet, a God, and you use me to measure temperature. What am I?
7. I can protect you from the sun’s strong rays. You can apply me on your skin to prevent sunburn. What am I?
8. What is black when you purchase it, red while you are using it, and gray when you discard it?
9. Kids really love me because I make things float. You can even use me to expand small things. What am I?