Question

water is essential for life. without water,
life as we know it would not exist.
use the pbs nova article to answer the
questions.
pure water freezes at 0° c (32° f) and boils at 100° c (212° f), a large range for a liquid,
and has an extremely high heat capacity. why are these properties of water important?
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why is it important that solid water, ice, floats rather than sinks?
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Explanation:

First Question (Why are water's freezing/boiling point and high heat capacity important?)

• Freezing/Boiling Point Range: A large liquid range (0–100°C) means water stays liquid in most Earthly environments, enabling life-sustaining processes (e.g., aquatic ecosystems, biochemical reactions in cells).
• High Heat Capacity: Water absorbs/releases large heat without rapid temperature change. This stabilizes Earth’s climate (oceans regulate temperature), maintains body temperature in organisms, and moderates daily temperature fluctuations in environments.

If ice sank, bodies of water (lakes, oceans) would freeze from the bottom up, killing aquatic life and disrupting ecosystems. Floating ice insulates the water below, keeping it liquid and allowing life to survive beneath, while also preventing complete freezing of water bodies over time.

Answer:

The large liquid range (0–100°C) keeps water liquid for life processes (e.g., aquatic habitats, cellular reactions). High heat capacity stabilizes climate, organism temperatures, and environmental temperatures by absorbing/releasing heat slowly.

Second Question (Why is it important ice floats?)