States of Matter

Solid GasLiquid

Questions

• What are the 3 states of matter?

• Write a definition for each state?

Everything in the universe is either MATTER or ENERGY.

• Matter is any thing that has mass and takes up space. All Matter is composed of one or more of over 100 elements in the periodic table.

• Elements are made of atoms • Atoms are made of protons (+)

electron (-) neutrons

Properties used to describe Matter

Energy• Energy: Energy can be built up (potential energy) or

converted into motion (kinetic energy). • Energy has several forms, and are mostly made up from

the Electromagnetic Spectrum.• Mechanical Energy Electrical energy Sound• Heat / thermal energy Light Radiation Magnetism• Chemical Nuclear

Defining States of Matter• States of matter are NOT defined by what they are made of.• Example: solids can be elements (gold), compounds (Salt = NaCl),

or mixtures (butter)

States of matter ARE defined by whether they hold SHAPE and VOLUME

Element (Au) Compound (NaCl) Mixture (Milk, Salt, etc)

Solids

• Solids – have a definite SHAPE and VOLUME. Solids keep their same shape and volume.

Element (Au) Compound (NaCl) Mixture (Milk, Salt, etc)

Particle View of a Solid

• Position of Molecules show: Particles in a solid are PACKED CLOSELY together and they are in a FIXED POSITION.

• Molecular motion shows some energy as the molecules vibrate

Particles vibrate in place

Liquids

• Liquids – has definite VOLUME but no defined SHAPE. Liquid conforms to whatever container they are placed in.

100 ml

Particle View of a Liquid• Position of Molecules : Packed CLOSELY

(like a solid), but move FREELY around each other (must stay in contact).

• Molecular motion shows some more energy as the molecules glide past one another

Gases• Gases - do NOT have definite SHAPE or

VOLUME. Gas will take the shape of whatever container it is placed.

Bromine gas fills up the entire volume of the container

Particle view of a Gas• Position of Molecules : Particles can

MOVE FREELY and will either fill up or squeeze into available space.

• Molecular motion: molecules move fast and collide into each other, more energy

Questions

• 1) Which Statement is True?– A) Liquids have a definite shape and volume– B) States of matter are defined by the

substances they are made up of– C) Gases have a definite shape and volume– D) Solids have a definite shape and volume

Task• Draw a diagram of

– A) Gas particles– B) Liquid particles– C) Solid particles

The Kinetic Molecular Theory: Particles are in constant motion. In solids the particles are close together and have limited motion. In a liquid some of the

attraction between particles is overcome which allows the particles more freedom of movement. In a gas particles attraction between particles is

minimized and the particles move freely throughout the container

Changes in States of Matter

• Thermal Energy – heat energy.

• More thermal energy = More particle movement

Changing States• Changing States of Matter is a Physical

Change because you can always return to a previous state.

• A change in ENERGY is what changes one state to another state.

Solid GasLiquid

Increase Thermal Energy (Heat up)

Decrease Thermal Energy (Cool off)

Phase Changes

Melting point

• Melting - change from solid to liquid• Melting point - SPECIFIC temperature when

melting occurs. • Each pure substance has a SPECIFIC melting

point.– Examples:– M.P. of Water = 0°C (32°F) – M.P. of Nitrogen = -209.9 °C (-345.81998 °F)– M.P. of Silver = 961.93 °C (1763.474 °F) – M.P. of Carbon = 3500.0 °C (6332.0 °F)

Melting Point

• Particles of a solid vibrate so fast that they break free from their fixed positions.

Solid Liquid

Increasing Thermal Energy

Melting point

Vaporization

• Vaporization – change from liquid to gas

• Vaporization happens when particles in a liquid gain enough energy to form a gas.

GasLiquid

Increasing Thermal Energy

Boiling point

Two Kinds of Vaporization

• Evaporation – vaporization that takes place only on the surface of the liquid

• Boiling – when a liquid changes to a gas BELOW its surface as well as above.

Boiling Point

• Boiling Point – temperature at which a liquid boils

• Each pure substance has a SPECIFIC boiling point.– Examples:– B.P. of Water = 100°C (212°F) – B.P. of Nitrogen = -195.79 °C (-320.42 °F)– B.P. of Silver = 2162 °C (3924 °F) – B.P. of Carbon = 4027 °C (7281 °F)

Boiling Point and Melting Point

Melting point

Boiling point

Solubility• Maximum amount of a substance that can

be dissolved in a liquid (at a specific temperature).

• Anything past the maximum, is called a saturated or even supersaturated solution, where you can see the solids in the liquid.

Salt (NaCl) Water (H20) at 20°C

Solubility• Solute – substance being dissolved

• Solvent – liquid substance that solute is dissolved into

• Solution- a homogeneous (thoroughly mixed) mixture composed of only one phase (sugar water)

• Mixture- Mixtures are things that are composed of two or more substances. Can be homogeneous like brass alloy (copper, lead, zinc, tin) or heterogeneous (not uniform- like mixed salt and pepper or sand)

Solubility

• Solute – ??????

• Solvent – ?????

Salt (NaCl) Water (H20) at 20°C

SaltWater

Solubility can change

• Increased Temp = Increased Solubility

• Different substances have different solubility curves

Solubility of Unknown Substance at different temperatures

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