How do isotopes affect an element's average atomic mass?

Agas at 155 kpa and standard temperature has an initial volume of 1.00 l. the pressure of the gas rises to 500 kpa as the temperature also rises to 135°c. what is the new volume? 2.16 l 0.463 l 0.207 l 4.82 l

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.

What is a metal replacement reaction