smiles:CCC(CC)O

Same atoms, joined differently. Every one of these is a separate compound with its own boiling point, smell and reactions. These are the ones PubChem has on file, which for a larger formula is fewer than the number that could exist on paper.

• 2-Methyl-2-butanol
• tert-Butyl methyl ether
• 1-Pentanol
• 2-Methyl-1-butanol
• Isoamyl Alcohol
• 3-Methyl-2-butanol
• 2-Pentanol
• 3-Pentanol
• Neopentyl alcohol
• Butyl methyl ether
• Ethyl isopropyl ether
• Ether, isobutyl methyl
• Ethyl propyl ether
• 2-Methoxybutane