Observing Phase Changes Science Worksheets printable pdf download

Observing Phase Changes Science Worksheets

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Observing Phase Changes

Purpose: To observe changes in energy as water changes state Background Information: Heat changes the temperature

of a substance. When heat is absorbed by a substance, the kinetic energy is of the substance is increased; the particles

(atoms and molecules) of the substance begin to speed up and move faster. The reverse is also true. When a substance

cools off, it releases, or loses, heat and the kinetic energy decreases. The particles slow down. Heat changes the state of

matter. A substance will change from one state or phase to another at specific combinations of temperature and

surrounding pressure. Usually, the pressure is atmospheric pressure, so temperature is the determining factor to the

change in state in those cases. There are 3 states of water which are liquid, solid and gas. All three states exist on earth.

There are names for each of the phase changes of water. They are:

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Water going from a solid to a liquid: Melting – absorbs heat

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Water going from a liquid to a gas: Evaporation – absorbs heat

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Water going from a solid to a gas: Sublimation – absorbs heat

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Water going from a liquid to a solid: Freezing – releases heat

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Water going from a gas to a liquid: Condensation – releases heat

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Water going from a gas to a solid: Deposition – releases heat

Prediction: When heat is added to ice, the ice will change state from solid, to liquid, to gas. What do you think a graph of

this data will show? Sketch it below:

Time

M. Poarch 2015

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Observing Phase Changes Science Worksheets