Final answer:
A grouping of two or more atoms bonded together is called a molecule, which can be a simple molecule like H₂, or a compound like H₂O if it consists of different elements.
Step-by-step explanation:
When two or more atoms bond together, they are known as a molecule. Atoms connect through a chemical bond which is a weak or strong electrical attraction that holds atoms close, making the resulting group more stable than separate atoms. An example of a simple molecule is molecular hydrogen, H₂, where two hydrogen atoms share electrons through a covalent bond. Meanwhile, a molecule composed of different elements, such as H₂O, where two hydrogens and an oxygen atom share electrons, is a chemical compound. In the example of water (H₂O), covalent bonds hold the atoms together, each hydrogen atom sharing electrons with the oxygen atom.