Which of these statements is true?
a.
some molecules may contain no atoms.
b.
some elements found in nature exist as molecules.
c.
some compounds include only one type of element.
d.
some atoms are made of two or more different elements.

The characteristics of two different types of reactions are shown below: reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of an element. which statement is true about the atoms of the elements that participate in the two reactions? their identity changes in both reaction a and reaction b. their identity changes in reaction a but not in reaction b. their identity changes in reaction b but not in reaction a. their identity remains the same in both reaction a and reaction b.

What is the indicator of the number of ions in solution? the amount of conductivity the amount of precipitate the amount of solute added

What must be in balance for temperatures to remain constant?