What are the six most important chemical elements of life?

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 __________.

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.

We can be sure that a mole of table sugar and a mole of vitamin C are equal in theira. mass.b. volume.c. number of atoms.d. number of molecules.

The reactivity of an atom arises froma. the average distance of the outermost electron shell from the nucleus.b. the existence of unpaired electrons in the valence shell.c. the sum of the potential energies of all the electron shells.d. the potential energy of the valence shell.