Matter & Energy Chapter 2 Enter
What are Matter and Energy? Joule 4.184 joules = 1 calorie matter – is material such as rocks, water, air with mass and occupying space. energy – is what makes matter move! Energy is measured in many different units. The metric unit of energy used by scientists is:
What is Matter? • Matter is anything that has mass and takes up space. • Objects made of matter have physical properties. • Physical properties are characteristics of a substance that can be seen or measured. Color, hardness, and taste are examples of physical properties. The physical properties of this orange are that it’s round, orange, and soft.
Partner Activity • Take a moment with your partner to name the physical properties of the pictured object. Check your answers.
Pyramid Physical Properties Triangular Purple Shiny Hard Heavy
Measuring Mass balance Mass is the amount of matter in an object. Mass is measured using a balance in grams. Mass of an object is always the same.
What is Weight? • Weight is a measure of the pull of gravity on an object. • Weight of an object can change. • Example: • A car that weighs about 2,698 lbs on earth weighs about 450 lbs on the moon due the difference in the force of gravity.
Measuring Mass by Volume • Volume is the amount of space that an object takes up. • Liquids can be measured using a graduated cylinder (see photo). • Solids can be measured by using a calculation. • Length x width x height
Volume • What if the object is an odd shape? • Volume of irregular shapes can be found by placing them in water. • Then, measure the amount of water that is displaced. Click to watch and learn.
Density Click to watch and learn. Density is the amount of matter in a certain volume. The density of an object always stays the same. Density = mass / volume
3 States of Matter • There are 3 states of matter that you are familiar with. • Solid • Liquid • Gas • Visit BBC’s website on the 3 states of mater.
Phases of Matter • the phases • solid • liquid • gas • plasma depend on how tightly bound the atoms and/or molecules are • As temperature increases, these bonds are loosened:
Temperature vs. Heat • Temperature is the average kinetic energy. • Heat (thermal energy) is the total kinetic energy. lower T higher T less heat more heat same T
Solid rock • Has a shape and a definite volume. • Feels firm when you touch it. • The particles are packed closely together. • Examples candy helmet
Liquid ocean • Has a definite volume but no definite shape. • The particles of a liquid move more freely. • Can change shape. • Examples soup soda
Gas • Gas does not have a definite shape or volume. • The particles are freer to move around and move the fastest. • Gas flows and takes the shape of the container.
Changes Between States of Matter • All substances can change states. • Liquids can freeze. Freezing changes a liquid to a solid.
Changes Between States of Matter • Melting changes a solid to a liquid. • Boiling changes a substance from a liquid to a gas.
A solution is a mixture in which different kind of matter mixed even with each other. Example: Adding sugar to water A solution can only be made when one substance dissolves. Click to visit the mixture lab. What is a Solution?
Physical changes occur when matter changes its property but not its chemical nature. Physical property changes are any change in size, shape or state of a substance. Physical Changes Sugar can undergo many physical changes. Even though each form is different, they are still sugar.
Chemical Changes • Burning is an example of a chemical change. • Light and warmth are released. Smoke, ash, and hot gases are produced.
Chemical Changes Chemical changes are changes matter undergoes when it becomes new or different matter. To identify a chemical change look for signs such as color change, bubbling and fizzing, light production, smoke, and presence of heat.
What is Energy? • Energy is the ability to do work. • Energy is the ability to cause changes in matter. • Light, sound, heat, and electricity are forms of energy. • Three categories of energy are: 1. Kinetic Energy • Potential Energy • Radiant Energy
Three Basic Types of Energy • kinetic • energy of motion • potential • stored energy • radiant • energy transported by light • Energy can change from one form to another.
Kinetic Energy • Amount of kinetic energy of a moving object • 1/2 mv2 [if mass (m) is in kg & velocity (v) is in m/s, energy is in joules] • On the microscopic level • the average kinetic energy of the particles within a substance is called the temperature. • it is dominated by the velocities of the particles.
Potential Energy E = mc2 [ c = 3 x 108 m/s is the speed of light; m is in kg, then E is in joules] energy is stored in matter itself this mass-energy is what would be released if an amount of mass, m, were converted into energy
Potential Energy g m d • gravitational potential energy is the energy which an object stores due to its ability to fall • It depends on: • the object’s mass (m) • the strength of gravity (g) • the distance which it falls (d)
Conservation of Energy Energy can be neither created nor destroyed. It merely changes its form or is exchanged between objects. This principle (or law) is fundamental to science. The total energy content of the Universe was determined in the Big Bang and remains the same today.
Energy Sources • It comes from many different sources. • Solar • Chemical • Water • Nuclear • Wind • Natural Gas • Fossil Fuels
Solar Energy • This is energy that comes from the sun. • All living things depend on this energy. • Does not damage the environment. • Can be used for heat and electricity. Click to watch and learn.
Chemical Energy • Energy stored in a substance and released during a chemical reaction such as burning wood, coal, or oil.
Hydroelectric (Water) Energy • Energy the comes from moving water. • Dams are built to store water and generate electricity. • Hydroelectric power is produced as water passes through a dam, and into a river below. The more water that passes through a dam, the more energy is produced.
Nuclear Energy • Energy that comes from splitting atoms of radioactive materials, such as uranium • Used to produce electricity.
Wind Energy • Wind is air moving around. • Wind is used to generate electricity. • Windmills are used to create this electricity. • Safe for the environment.
Fossil Fuels • Fuels (coal, oil, natural gas, etc.) that result from the compression of ancient plant and animal life formed over millions of years. • Fossil fuels are oil, coal, natural gas, and uranium.
Nonrenewable Energy • This means that this type of energy cannot be made again. • An energy source that we are using up and cannot recreate in a short period of time. • Nonrenewable Energy Sources: • nuclear • oil • coal • natural gas
Renewable Energy • This type of energy can be replenished. • An energy source that we can use over and over again. • Renewable Energy Sources: • solar • wind • water
Electric Energy • Electric energy is the energy produced by the movement of electrons. • When an object gains or loses electrons, it has an electric charge.
Electric Energy When an object has a charge, it attracts objects with the opposite charge. This is called an electrical force. An electric current is the flow of electrons from negatively charged objects to positively charged objects.
Electric Current An electric current is the flow of electrons. To light a light bulb or run a computer, you need a continuous electric current. A battery or generator can be the source of electrons.
Electric Energy • Conductors of electricity are materials that carry electrons easily from one terminal to another. • A conductor is used in the wire that makes an electric circuit. An electric circuit is any path in which electrons can flow.