At what temperature does pure ice melt under standard atmospheric pressure?

• A. 0~^ext{o}ext{C}
• B. -10~^ext{o}ext{C}
• C. 32~^ext{o}ext{C}
• D. 100~^ext{o}ext{C}

Answer: (A)

Verified step by step guidance

1. Understand that the melting point of a substance is the temperature at which it changes phase from solid to liquid under a given pressure, typically standard atmospheric pressure (1 atm).
2. Recall that pure ice (solid water) melts at a specific temperature under standard atmospheric pressure, which is a well-established physical property.
3. Recognize that the melting point of ice is commonly used as a reference point in temperature scales, especially the Celsius scale.
4. Identify that the melting point of pure ice under 1 atm pressure is 0~^\text{o}~\text{C}, meaning ice melts at zero degrees Celsius.
5. Note that the other temperature options (-10~^\text{o}~\text{C}, 32~^\text{o}~\text{C}, 100~^\text{o}~\text{C}) correspond to temperatures that are either below freezing, the freezing point of water in Fahrenheit, or the boiling point of water, respectively.