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Introduction to Kinetic Energy. Temperature and Heat : not the same. And Pressure. Matter in motion. The idea that the particles (atoms and molecules) of all matter are small round spheres in constant, random motion is called the kinetic theory of matter. Kinetic Theory of Matter.
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Introduction to Kinetic Energy Temperature and Heat: not the same. And Pressure.
Matter in motion • The idea that the particles (atoms and molecules) of all matter are small round spheres in constant, random motion is called the kinetic theory of matter.
Kinetic Theory of Matter • All matter is made of atoms and molecules which we can think of hard round spheres. • These particles are always in motion. • The higher the temperature, the faster the particles move.
Temperature • Temperature is a measurement of the average kinetic energy of these particles.
TEMPERATURE measures the direction of heat flow. • Heat always flows from the higher temperature matter to the lower temperature matter. • As heat flows FROM one kind of matter, that kind of matter cools, while the second kind warms. • The hot object cools, the cool object warms, and the final temperature is the same for both.
Evaporation vs vaporization vs boiling • Vaporization: any conversion of liquid to gas at any temperature. • The specific term for vaporization of a liquid below its boiling point is evaporation. • The specific term for vaporization at or above the temperature at which visible amounts of liquid are becoming gas is boiling.
Heat is a form of energy. • Heat can be generated from other forms of energy: light, mechanical, chemical potential energy, etc. • According to the LAW OF CONSERVATIONOF MASS ANDENERGY, energy (heat) cannot be created or destroyed; it can only be transformed into other types of energy.
There are two forms of energy. • One involves ACTUAL motion, and that is KINETIC ENERGY.(K.E.) • The other involves the stored ability to move: POTENTIAL ENERGY. Measure energy in Joules and calories • The JOULE is the SI unit of measurement for energy • Energy required to accelerate at object of 1 kg to a distance of 1 meter in 1 second.
Calories and calories • 1 calorie is the amount of heat needed to raise the temperature of 1 gram of water 1 oC • Calorie: dietary & 1000x as much energy as calorie with a small calorie (1 kcalorie) • 1 cal = 4.18 J • 1Cal = 1000 cal (food calories) • TEMPERATURE IS NOT THE SAME THING AS HEAT.
Pressure • Moving bodies exert a force when they collide with other moving bodies • Pressure = Force per unit area • The SI unit of measurement is the KPa. • We also measure pressure in atmospheres, mm Hg (torr), inches of Hg, psi
Gas Pressure • Gas pressure is a result of molecules and atoms colliding with the walls of a container.
Units of pressure • Atmospheric pressure measure on a barometer • 1 atmosphere of pressure(atm) will support a column of mercury (Hg) to a height of 760 mm Hg, = 76.0 cm, = .760 m. • This means that collision of air particles on an open pool of mercury will allow and cause the mercury to stand in a column closed at the top & containing NOTHING but Hg(l) and Hg(g) to a height of 760 mm.
1 atm = 101.3 kPa = 760 mm Hg =14.7 psi = 29.92 in Hg • Pascal is the SI unit for pressure • Newton/ meter2 which is very small, therefore we often use the kiloPascal • 101,305 Pa = 1 atm = 101.3 KPa • How many mm Hg are there in 202.6 kPa? • How many kPa are there in 400 mmHg?
1 atm = 760 mm • How many mm Hg would 2 atm be? 2atm / 760 mmHg = 1520 mmHg 1 1 atm
Convert 3.75 atm to ___KPa • 3.75 atm 101.305 kPa = 380.kPa 1 atm
States of Matter Chemistry The Four States of Matter Chumbler - Properties of Matter
The Four States of Matter Four States Solid Liquid Gas Plasma Chumbler - Properties of Matter
The Four States of Matter Basis of Classification of the Four Types Based upon particle arrangement Based upon energy of particles Based upon distance between particles Chumbler - Properties of Matter
Solids • Particles of solids are tightly packed, vibrating about a fixed position. • Solids have a definite shape and a definite volume. • Solids have an infinite number of free surfaces. • EX: Chumbler - Properties of Matter
Liquids • Particles of liquids are tightly packed, but are far enough apart to slide over one another. • Liquids have an indefinite shape and a definite volume. • Liquids have one free surface. • EX: Chumbler - Properties of Matter
Gases • Particles of gases are very far apart and move freely. • Gases have an indefinite shape and an indefinite volume. • Gases have no free surfaces. • EX: Chumbler - Properties of Matter
Plasma • A plasma is an ionized gas. • A plasma is a very good conductor of electricity and is affected by magnetic fields. • Plasma, like gases have an indefinite shape and an indefinite volume. • EX: stars, lightning, sun Particles The negatively charged electrons (yellow) are freely streaming through the positively charged ions (blue). Chumbler - Properties of Matter
Plasma Examples Chumbler - Properties of Matter
Microscopic Explanation for Properties of Solids Solids have a definite shape and a definite volumebecause the particles are locked into place Solids are not easily compressible because there is little free space between particles Solids do not flow easily because the particles cannot move/slide past one another Chumbler - Properties of Matter
Microscopic Explanation for Properties of Liquids Liquids have an indefinite shape because the particles can slide past one another. Liquids are not easily compressible and have a definite volume because there is little free space between particles. Liquids flow easily because the particles can move/slide past one another. Chumbler - Properties of Matter
Microscopic Explanation for Properties of Gases Gases have an indefinite shape and an indefinite volume because the particles can move past one another. Gases are easily compressible because there is a great deal of free space between particles. Gases flow very easily because the particles randomly move past one another. Chumbler - Properties of Matter
Microscopic Explanation for Properties of Plasmas Plasmas have an indefinite shape and an indefinite volume because the particles can move past one another. Plasmas are easily compressible because there is a great deal of free space between particles. Plasmas are good conductors of electricity and are affected by magnetic fields because they are composed of ions (negatively charged electrons and positively charged nuclei). Chumbler - Properties of Matter
The Four States of Matter The Classification and Properties of Matter Depend Upon Microscopic Structure Particle arrangement Particle energy Particle to particle distance Chumbler - Properties of Matter