2. Cell Chemistry & Cell Components

What is generally true about essential elements and living organisms?

The number of protons in an uncharged atom __________.

Which of the following subatomic particles has appreciable mass but no charge?

Which of the following has negligible mass?

What are the four most abundant elements found in living systems?

Which of the following is a trace element?

If you were told that concentrations of trace elements above what is required by organisms generally have no effect on those organisms, what would you say?

There are __________ naturally occurring elements.

An element has eight protons, nine neutrons, and eight electrons. Its atomic number and atomic mass, respectively, are __________.

An uncharged atom of nitrogen (atomic number = 7) has __________.

What are the six most important chemical elements of life?

In the term trace element, the adjective trace means thata. the element is required in very small amounts.b. the element can be used as a label to trace atoms through an organism's metabolism.c. the element is very rare on Earth.d. the element enhances health but is not essential for the organism's long-term survival.

Fill in the blanks in this concept map to help you tie together the key concepts concerning elements, atoms, and molecules.