Now does a rubber rod become negatively charged through friction

You are working in the lab and are working with the same element but with varying isotopes of the element. you are working with c-11, c-13, c-14, and c-15. what is the average atomic mass of this element? (use periodic table) a- 12 b-15 c-14 d-13

In which state was more than 100 billion tons of coal mined in 2005?

Hershey and chase confirmed that dna, not protein, was the genetic material. how do the results of their two experiments support this conclusion?