Answer: Neon has the LOWEST melting point, and water has the HIGHEST boiling point among the given substances.
Explanation: Based on the information provided, we can determine the substances with the lowest melting point and the highest boiling point among neon, argon, oxygen, and water.
The substance with the LOWEST melting point would be neon (symbol: Ne). Neon is an inert gas and has a very low melting point of -248.59 degrees Celsius or -415.46 degrees Fahrenheit.
The substance with the HIGHEST boiling point would be water (symbol: H2O). Water has a boiling point of 100 degrees Celsius or 212 degrees Fahrenheit at standard atmospheric pressure. This is higher compared to the boiling points of neon, argon, and oxygen.
Therefore, neon has the LOWEST melting point, and water has the HIGHEST boiling point among the given substances.