Physical Science Chapter 3
Bellwork Pre-test
States of Matter States of Matter: Materials can be classified as solids, liquids, or gases based on whether their shapes and volumes are definite or variable.
Solids Solid: a state od matter in which the materials have definite shape and a definite volume.
Solid
Definite* Definite: the shape and volume of a material won’t change when you move it Definite does not mean it will never change Almost all solids have a closely packed atomic arrangement
Solid, Liquid, Gas
Liquids Liquid: the state of matter in which a material has a definite volume, but not a definite shape
Liquid
Liquid Liquid: takes the shape of the container it is in It does not change its volume to fit the container
Liquid
Liquid
What is the main difference between the different states of matter? Bellwork What is the main difference between the different states of matter?
Gases Gas: a state of matter in which a material has neither a definite shape nor a definite volume
Read the paragraph about gas Gas: more space between atoms Gas can be compressed into smaller spaces Gas spreads out when released from compaction
Gas
Almost all matter on Earth is solid, liquid, or gas. Other states of matter Almost all matter on Earth is solid, liquid, or gas. 99 % of the universe matter at high temperatures is in the form of plasma
Plasma
Plasma
Homework/classwork Complete your work/study book pages 25-26 questions 1-10
Create a Comparison Chart Liquid Gas Solid Look back at your notes and the book and tell whether each state has definite volume, definite shape, variable volume, or variable shape.
Directions Look back at your notes and the book and tell whether each state has definite volume, definite shape, variable volume, or variable shape.
What makes plasma so different from the other states of matter? Bellwork What makes plasma so different from the other states of matter?
Kinetic Theory Kinetic energy: is the energy an object has due to its motion (comes from the Greek word “to move”)
The faster an object moves, the greater the kinetic energy is. Kinetic Theory The faster an object moves, the greater the kinetic energy is. A baseball thrown at 85 mph has more kinetic energy than one thrown at 75 mph The kinetic theory suggests that the materials in the ball are moving too
Kinetic Theory Kinetic Theory of Matter: all particles of matter are in constant motion
Behavior of Gases Like the game of pool
Motion in gases At room temperature, the average speed of particles of gas is 1600 kilometers per hour 994 mph!
Motion in Gases Not all atoms move at the same speed, but the kinetic energy remains the same
Two helium atoms bounce around the jar. Look on page 72 Two helium atoms bounce around the jar. They collide with each other and the jar. One may lose speed while the other gains speed. The total energy remains the same!
There are forces of attraction among the particles in all matter. The faster the particles are moving (like in gas) these forces of attraction are not as strong
Kinetic Theory of Gases The constant motion of particles in a gas allows a gas to fill a container of any shape or size.
Kinetic Theory of Gases 3 Points 1: Particles in a gas are in constant, random motion 2. The motion of one particle is unaffected by the motion of the other particles unless the particles collide. 3. Forces of attraction among particles in a gas can be ignored under ordinary conditions.
Air Freshener We will divide into groups Groups will go to different corners of the room I will spray the air freshener in a far corner of the room and we will see how long it takes for the gas particles to travel to each corner
Mass of an element can have an effect on movement Behavior of Liquids Mass of an element can have an effect on movement Mercury (which is a liquid at room temperature) has 50 times the mass of a helium atom
Behavior of a liquid The arrangement of the atoms has an effect on movement The particles of a liquid are much closer together than particles of a gas This makes the power of attraction much greater
What is the Kinetic Theory of Matter? Bellwork What is the Kinetic Theory of Matter?
Behavior of Liquids A liquid takes the shape of its container because particles in a liquid can flow to new locations. The volume of a liquid is constant because forces of attraction keep the particles close together
Behavior of Solids Compare the activity of solid particles to that of people in a movie theater
Behavior of Solids Solids have definite shape and definite volume because particles in a solid vibrate around fixed locations
Quick assessment Write at least two paragraphs (5-7 complete sentences each paragraph) explaining how the kinetic theory can be used to explain the general characteristics of solids, liquids, and gases. This will be graded as a quiz ;-)
Pressure is the result of a force distributed over an area
Pressure Speed affects pressure: the faster something is moving the greater the pressure is
Pressure Area affects pressure: the smaller the area of impact, the greater the pressure
Force is measure in newtons (N) Area is measured in m2 SI Units Pressure = Force/Area Force is measure in newtons (N) Area is measured in m2 The SI unit for pressure is the pascal (Pa) Pa=N/m2
Factors that affect gas pressure Factors that affect the pressure of an enclosed gas are its temperature, its volume, and the number of its particles
Think of a car tire on the road Temperature Raising the temperature of a gas will increase its pressure if the volume of the gas and the number of particles are constant Think of a car tire on the road
Temperature and gas
Volume Reducing the volume of a gas increases its pressure if the temperature of the gas and the number of particles are constant. Empty plastic bottle
Volume and gas pressure
Number of particles Increasing the number of particles will increase the pressure of a gas if the temperature and the volume are constant
Complete your workbook up to number 18 on page 26 Complete your workbook up to number 18 on page 26. Complete the section assessment on page 74 in your book Due tomorrow