Question

question 1
1 pts
when heating some water, you may have noticed small bubbles forming at the bottom of the pot well before the water is at the temperature for boiling. what are those bubbles composed of?
hydrogen and oxygen as the water decomposes.
the water is boiling below its boiling temperature.
air (mostly nitrogen and oxygen) that was dissolved in the water and is released as the water warms.

Explanation:

1. Analyze the first option: Water decomposition requires high energy (like electrolysis), not just heating, so this is incorrect.
2. Analyze the second option: Boiling occurs at the boiling point (for a given pressure), so water can't boil below its boiling temperature, making this wrong.
3. Analyze the third option: Water dissolves air (nitrogen, oxygen, etc.). As water warms, solubility of gases decreases, so dissolved air is released as bubbles. This matches the observation.

Answer:

C. Air (mostly nitrogen and oxygen) that was dissolved in the water and is released as the water warms.