The Kinetic Theory of Matter explains the properties of solids, liquids, & gases
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The Kinetic Theory of Matter explains the properties of solids, liquids, & gases. The Kinetic Theory of Matter. Based on idea that particles of matter are in constant motion. Describes properties of solids, liquids, & gases in terms of the FORCE of the particles

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The Kinetic Theory of Matter explains the properties of solids, liquids, & gases

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The kinetic theory of matter explains the properties of solids liquids gases

The Kinetic Theory of Matter explains the properties of solids, liquids, & gases


The kinetic theory of matter

The Kinetic Theory of Matter

Based on idea that particles of matter are in constant motion.

Describes properties of solids, liquids, & gases in terms of the FORCE of the particles

The constant random motion of tiny particles called Brownian motion


Physical behavior of matter

Physical Behavior of Matter

Section 10.1


States of matter

States of Matter

  • Four states of matter


Solids

Solids

  • Particles-closely packed; can’t be compressed

  • Voids - extremely small

  • Particle motion is vibratorymotion; definite shape & volume

  • Apply heat-particles vibrate more & move SLIGHTLY farther apart; causes solid to expand


Kinetic model of solids

Kinetic Model of Solids

STRONG intermolecular forces result in rigid structure of solids

Particles move (vibrate) but not past each other

Particles occupy fixed 3-D positions that repeat throughput the solid

3-D arrangement = crystal lattice


Liquids

Liquids

  • Flowing matter w/ definite volume & indefinite shape

  • Particles have weak bonds that keep them close; more space to move; particles able to move relative to each other

  • When heat applied, liquids expand a little


Kinetic model of liquids

Kinetic Model of Liquids

Particles of liquid slide past each other; consider magnetized spheres

Intermolecular forces maintain their volume NOT shape


Gases

Gases

  • Flow, too (consider wind)

  • Particles far apart; complete freedom of movement

  • Motion is random

  • No definite shape/volume

  • Easily compressed into smaller volume

  • Expand & contract in response to temperature changes more so than liquids & solids


Kinetic model of gases

Kinetic Model of Gases

Particles in gas in constant, random motion

Change direction ONLY when they strike wall of container OR another gas particle (Air-hockey puck)

Density (M/V) in gas lower than solid

Few particles in gas vs solid of same volume (due to space between particles)


5 assumptions of the kinetic theory

5 Assumptions of the Kinetic Theory

Gases are made of molecules in constant, random movement.

LARGE portion of the volume of a gas = empty space. The volume of all gas molecules, in comparison, is negligible.


5 assumptions of the kinetic theory1

5 Assumptions of the Kinetic Theory

The molecules show no forces of attraction or

repulsion (UNLIKE solids & liquids).

No energy is lost in collision of molecules; the impacts are completely elastic.

The temperature of a gas is the average KE of all of

the molecules.


Ideal gases

Ideal Gases

  • Ideal gases = gases that obey the assumptions of the kinetic theory

  • Except for temperatures extremes, most real gases behave like ideal gases

  • At temperature extremes, forces between particles & particle size begin to matter

  • At temperature extremes gases no longer follow the assumptions of the kinetic theory


Gases pressure temperature volume

Gases & Pressure, Temperature, & Volume

  • KToM explains gas pressure = the total force exerted by gas molecules colliding against the walls of a container.

  • IF the container can expand, like a balloon/tire,

    in pressure can the volume; THUS the balloon/tire will get BIGGER .

  • If you the temperature of the gas, the KE of its molecules &, the pressure/volume


Gases pressure temperature volume1

Gases & Pressure, Temperature, & Volume

  • There is a relationship between pressure, volume and temperature in an ideal gas

  • If you the pressure & hold the volume constant, the temperature (principle of a refrigerator)

  • If you the temperature & hold the pressure constant, the volume (heating a balloon)


Earth s atmosphere and pressure

Earth’s Atmosphere and Pressure

  • We’re at the bottom of an ocean of air

  • Atmospheric pressure = force exerted on us by molecules of air (14.7 lbs/square inch)

  • Atmospheric pressure related to column of air;

  • As elevation ↑ pressure↓

  • As elevation ↓, pressure ↑

  • How does atm pressure affect YOU?


Other forms of matter

Other Forms of Matter

  • Amorphous Solids = arrangement of molecules is fairly random; so, crystal lattice is loosely packed ; haphazard, disjointed

  • Examples = GLASS,

cotton candy

Wax/Candles


Liquid crystals

Liquid Crystals

  • When solids melt, the crystal lattice disintegrates; particles lose their 3-D pattern

  • Liquid crystals-NOT liquid OR solid

  • When melted LCs lose their rigid organization in 1 or 2 dimensions NOT all 3 dimensions

  • Interparticle forces in liquid crystals are relatively weak; when forces in lattice are broken, crystals can flow like liquids

  • Liquid crystal displays (LCDs) used in TVs, watches, calculators, thermometers, etc.


Plasmas

Plasmas

  • Form at very temperatures

  • Plasma = gas that has been energized; some e- break free from, but travel w/their nucleus

  • Plasma = free e- & ions of that element.

  • Gases can become plasmas in several ways, ALL include pumping the gas w/ energy.

  • Examples = stars, fluorescent tubes, neon lights, etc.


Examples of plasma

Examples of Plasma


Energy and changes of state

Energy and Changes of State

Section 10.2


Temperature kinetic energy particle motion

Temperature & Kinetic Energy & Particle Motion

  • Temperature = measure of the average kinetic energy of particles in a material

  • When heated liquid & gas particles have more kinetic energy BUT not all particles have the same kinetic energy; particles are moving at different speeds

  • Generally, as temperature matter moves to a more active state; as temperature matter moves to a less active state


The kelvin scale

The Kelvin Scale

  • Absolute zero = temperature at which a substance would have zero (or very little) kinetic energy

  • Kelvin Scale = used for temperature; it is defined so temperature of a substance is directly proportional to the average kinetic energy of the particles

  • 0 on Kelvin scale = absolute zero & measured as Kelvins; divisions on Fahrenheit & Celsius scale are measured in degrees

  • Celsius degree & Kelvins = the same size; absolute zero = -273.150C

  • Kelvin scale measures everything ABOVE absolute zero; all numbers are positive


Temperature conversions

Temperature Conversions

  • When converting from kelvin (K or TK) to Celsius (C or TC), and vice versa, the magic number is 273!!

  • K= (0C+ 273); K= (150C+ 273) = 288 K

  • 0C= (K- 273); 0C= (320 K - 273) = 470C


Mass speed of particles

Mass & Speed of Particles

KE of gas depends on mass & speed of particles

1. Gases at SAME temp have SAME average KE

2. LARGER gas molecule simply moves SLOWER than SMALL gas molecule

Ex: O2 = 16x more massive than H2; at SAME temp, H2 moves FASTER than O2


Mass speed of matter

Mass & Speed of Matter

  • Random motion causes particles to spread out to fill a container

  • DIFFUSION = the process in which these particles fill a space

  • Particles move from areas of high concentration to areas of low concentration

  • Rate of diffusion of a gas dependent upon the KE of that gas/substance


Changes of state

Changes of State

TRIPLE POINT = The single specific temperature & pressure at which all 3 phases can co-exist

CRITICAL POINT = The conditions where gas & liquid become indistinguishable

Different phases of a system may be represented using a phase diagram.

Axes of the diagrams are typically pressure & temperature


Phase diagram for water

Phase Diagram for Water


Changes of state1

Changes of State

  • EVAPORATION

  • particles of a liquid form a gas by escaping from the surface

  • 3 things affect evaporation rate? Area of the surface, temperature, humidity

  • Volatile liquids evaporate quickly (perfumes, paint)

  • As liquids evaporate, they cool

Heating Curve-based on standard temp & pressure


Changes of state2

Changes of State

MELTING

The process of heating a SOLID substance to a point where it turns LIQUID.

FREEZING is the opposite of melting. It is the process of REMOVING heat from a liquid & turning the liquid into a solid.

The freezing point is the SAMETEMPERATURE as the melting point.

Heating Curve-based on standard temp & pressure


Changes of state3

Changes of State

  • Sublimation-process by which particles in a solid change to gaseous state w/o melting

  • Condensation-reverse of evaporation; gaseous particles become close (condense) & form a liquid


Specific heat

Specific Heat

  • To change the temperature of a SOLID

    2.1 Joules/g0C

  • To change the temperature of a LIQUID

    4.2 Joules/g0C

  • To change the temperature of a GAS

    2.02 Joules/G0C

    Heat = mass x specific heat x temperature change

    Q = m x c x (Tf –Ti)


Heat of vaporization

Heat of Vaporization

  • The amount of heat required (absorbed by the liquid) to convert unit mass of a liquid into its vapor w/o a change in temperature.

  • 2260 Joules = ENREGY needed to move the molecules in 1 g of water FAR enough apart that they form water vapor (JOULE, J,= SI unit of energy required to lift a 1-g mass 1m against the force of gravity)

  • Heat of Vaporization (Hv) of H2O = 2260 J/g


Heat of vaporization of water hv 2260 j g

Heat of Vaporization of Water Hv = 2260 J /g

  • The diagram right shows the uptake of heat by 1 kg of H2O, from ice at -50 ºC  to steam above 100 ºC.

    A: Rise in temp. as ice absorbs heat.B: Absorption of latent heat of fusion.C: Rise in temp. as liquid H2O absorbs heat.D: Water boils & absorbs latent heat of vaporization.E: Steam absorbs heat & thus increases its temperature.


Heat of fusion

Heat of Fusion

  • The heat nrg which must be removed to solidify a liquid or added to melt a solid

  • Melting point=temperature of the solid when its crystal lattice begins to break apart (intermolecular forces are overcome & solid becomes a liquid)

  • Freezing Point= temperature of liquid when it begins to form a crystal lattice & becomes a solid


The kinetic theory of matter explains the properties of solids liquids gases

Heating Curve


Phase diagram

Phase Diagram


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