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Section 1 The Cycles of Matter

Bellringer

What are the three different physical states of water that are found on Earth? Name one way that you use water in each of these states in your daily life.

Write your answers in your science journal.

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Section 1 The Cycles of Matter

BellringerClassify the following reactions as one of the following: synthesis, decomposition, single replacement, double replacement:1. CO + O2 CO2 2. KI + Cl2 KCl +I2 3. NaNO3 NaNO2 + O2

4. FeS + HCl FeCl2 + H2S

Write your answers in your science journal.

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Understand that, in normal conditions, water can exist in three different states.

Compare solids, liquids, and gases in terms of having a fixed shape or volume.

Describe the phase changes that occur when heat is added to or removed from water.

Compare the structure, spacing, and motion of molecules in solids, liquids, and gases.

Objectives

MS-PS1-2

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• Today we will:• Complete a do now• Complete a gizmo on Phase Changes

Agenda

MS-PS1-2

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• Phase change• exothermic• edothermic

Vocabulary

MS-PS1-2

Change of State

• Change of state is the change of a substance from one physical form to another.

ALL CHANGES OF STATE ARE PHYSICAL CHANGES

Melting(endothermic) heat in

• Melting is the change of state from a solid to a liquid.

Adding energy to a solid increases the temperature. As the temperature increases, the particles of the solid move faster and faster. Once the substance reaches it’s MELTING POINT, it becomes a liquid.

Boiling(endothermic) heat in

• Boiling is the change of a liquid to a vapor or gas.

• Boiling occurs when the vapor pressure of the substance reaches the atmospheric pressure. The temperature at which this occurs is called the boiling point.

Sublimation(endothermic) heat in

• Sublimation is the change of state where a solid turns directly into a gas. Skipping the liquid phase.

• During sublimation, the particles must gain enough energy to overcome their attraction, going from being very tightly packed together (as a solid) to rapidly moving and spreading apart (as a gas).

Freezing(exothermic) heat leaving

• Change of state from a liquid to a solid.

• Freezing is the reverse of melting so the melting point and freezing point for a substance is the same.

• During the freezing process, energy is removed from the substance causing the particles to slow which creates an attraction between them. The particles slow until they lock (or freeze) into place.

Evaporation

• Evaporation is the change of a substance from a liquid to a gas.

• Evaporation does not mean boiling. A substance can evaporate without boiling, for example sweat.

Condensation(exothermic) heat leaving

• Condensation is the change of state from a gas to a liquid.

• The condensation point is the temperature at which a gas becomes a liquid.

• During condensation, the fast moving particles of a gas clump together as energy (or heat) is removed.

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Section 3 Changes of StateChapter K2