Which of the following is not required for a contaminant to be effective?

The big bang nucleosynthesis theory states that elements were produced in the first few minutes of the big bang while elements have their origins in the interiors of stars, forming much later in the history of the universe.

How many grams of aluminum will there be in 98g of al2o3?

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.