Chemistry Assignment for 7th grade. (ch. 4)

Please answer the following question briefly.

1. What is meant by atom?
2. How is atom arranged?
3. Please define "isotopes"?
4. Please give the example of isotopes?
5. What is noble gas?
6. What is meant by atomic power?
7. Please define the meaning of "fusion reaction"!
8. How can an atom become positively charged or negatively charged?

You may find the answer from any sources. Please submit it before Sunday (April 7th, 2013) by sending your answers to edmsby85@yahoo.com. Don't forget to put your name on your answer page.