Why isn't the atomic mass of most of the elements on the periodic table a whole number?

Which part of a feedback mechanism is able to monitor the conditions outside of cells and usually uses nerve cells to relay this information to an intergrating center

Using the periodic table, complete the table to describe each atom. type in your answers

In an investigation that uses the scientific method, which step immediately follows making a hypothesis? o summarizing the results o asking a question o making observations designing an experiment mark this and retum save and exit next submit