Energy Basics
Energy Is the Ability To Do Work
Energy comes in different forms:- Heat (thermal)
- Light (radiant)
- Motion (kinetic)
- Electrical
- Chemical
- Nuclear energy
- Gravitational
Energy is in everything. We use energy for everything we do, from making a jump shot to baking cookies to sending astronauts into space.
There are two types of energy:
- Stored (potential) energy
- Working (kinetic) energy
For example, the food you eat contains chemical energy, and your body stores this energy until you use it when you work or play.
Energy Sources Can be Categorized As Renewable or Nonrenewable
When we use electricity in our home, the electrical power was probably generated by burning coal, by a nuclear reaction, or by a hydroelectric plant at a dam. Therefore, coal, nuclear and hydro are called energy sources. When we fill up a gas tank, the source might be petroleum or ethanol made by growing and processing corn.Energy sources are divided into two groups — renewable (an energy source that can be easily replenished) and nonrenewable (an energy source that we are using up and cannot recreate). Renewable and nonrenewable energy sources can be used to produce secondary energy sources including electricity and hydrogen.
Renewable Energy
Renewable energy sources include:- Solar energy from the sun, which can be turned into electricity and heat
- Wind
- Geothermal energy from heat inside the Earth
- Biomass from plants, which includes firewood from trees, ethanol from corn, and biodiesel from vegetable oil
- Hydropower from hydroturbines at a dam
Nonrenewable Energy
We get most of our energy from nonrenewable energy sources, which include the fossil fuels — oil, natural gas, and coal. They're called fossil fuels because they were formed over millions and millions of years by the action of heat from the Earth's core and pressure from rock and soil on the remains (or "fossils") of dead plants and creatures like microscopic diatoms. Another nonrenewable energy source is the element uranium, whose atoms we split (through a process called nuclear fission) to create heat and ultimately electricity.We use renewable and nonrenewable energy sources to generate the electricity we need for our homes, businesses, schools, and factories. Electricity "energizes" our computers, lights, refrigerators, washing machines, and air conditioners, to name only a few uses.
Most of the gasoline used in our cars and motorcycles and the diesel fuel used in our trucks are made from petroleum oil, a nonrenewable resource. Natural gas, used to heat homes, dry clothes, and cook food, is nonrenewable. The propane that fuels our outdoor grills is made from oil and natural gas, both nonrenewable.
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| Microscopic view of a gas. | Microscopic view of a liquid. | Microscopic view of a solid. |
- Particles in a:
- gas are well separated with no regular arrangement.
- liquid are close together with no regular arrangement.
- solid are tightly packed, usually in a regular pattern.
- Particles in a:
- gas vibrate and move freely at high speeds.
- liquid vibrate, move about, and slide past each other.
- solid vibrate (jiggle) but generally do not move from place to place.
| Some Characteristics of Gases, Liquids and Solids and the Microscopic Explanation for the Behavior | ||
|---|---|---|
| gas | liquid | solid |
| assumes the shape and volume of its container
particles can move past one another |
assumes the shape of the part of the container which it
occupies
particles can move/slide past one another |
retains a fixed volume and shape
rigid - particles locked into place |
| compressible
lots of free space between particles |
not easily compressible
little free space between particles |
not easily compressible
little free space between particles |
| flows easily
particles can move past one another |
flows easily
particles can move/slide past one another |
does not flow easily
rigid - particles cannot move/slide past one another |
Physical and Chemical changes in matter
We are going to discuss about physical and Chemical changes in matter concept . Matter undergoes certain changes as a result of the application of energy. Water from saltpans on the seacoast dry up, leaving behind salt; water from the sea evaporates to from water vapour, which convert into clouds and then condense to form rain. Glaciers melt in summer and rivers freeze in winter. A candle upon burning gives light, heat, water vapour and carbon dioxide. Hydrogen burns in air to form the water molecule H2O.
The different changes that matter undergoes, may be broadly classified into 'physical' and 'chemical' changes.Physical changes
When the shape, size, appearance or state, of a substance is altered, but its chemical composition remains same a physical
change
of matter takes place. No new substance is formed. It is usually a
change, which is reversible, that is, by reversing the
process, the original substance can be obtained.
By using a piece of gold, a goldsmith can make a gold chain and can later alter it to make a gold bracelet, ring or a pair of
earings. All of them consist of the same substance, namely gold. This is an example of a physical change. A more common
everyday example is that of water, which can be converted into solid ice, liquid water, and gaseous water vapor. It can be
reconverted
to its previous state by various methods. Yet, in all the three forms,
the chemical composition of water is not altered.
No new substance with new chemical properties is formed. In all these, water consists of two atoms of hydrogen and one atom
of oxygen.
Thus,
a Physical change is a change in which the chemical composition of the
substance is not affected, i.e., no new substance is formed.
Examples of Physical Changes
(a) Dissolving of sugar in water
When
crystalline sugar is dissolved in water, it seems to disappear
completely, and not even a very powerful microscope can show us the
molecules of sugar in water. The solution obtained is uniformly sweet.
By evaporating the water the sugar can be recovered in a crystalline
form.
(b) Magnetising an iron rod
An
iron rod can be converted into a magnet by passing an electric current
through an insulated coil wound around it. When the current flows, the
iron bar gets magnetised. One end becomes North Pole and the other the
South Pole. If the direction of the current is reversed, the North Pole
changes to South Pole and the South Pole changes to North Pole.
(c) Glowing of an electric bulb
When
an electric current is passed through the filament of a bulb, the
filament starts glowing and the glow stops as soon as the current is cut
off. The chemical composition of the filament does not alter in either
state.
Chemical Change
A change in which the composition of a substance is altered is called as chemical change of matter. As a result, the original
properties get changed and one or more new substances are formed.
Iron
is greyish white metal and conducts electricity. It is attracted by a
magnet, and reacts with dilute acids to yield hydrogen.
Sulphur is a non-metal, and is yellow in colour. It dissolves in carbon disulphide. When powdered iron and sulphur are heated
together,
a completely new substance, iron sulphide is formed. The properties of
iron sulphide are entirely different from those of
iron
and sulphur. It is black in colour, does not get attracted by a magnet
and does not allow electric current to pass through it.
It reacts with dilute acids to from hydrogen sulphide gas. In short,
the properties of neither iron nor sulphur are exhibited by iron
sulphide.
Conditions For Chemical Change
The criterion for a chemical change is the production of one or more new substances. Therefore, certain conditions should be
met in order to bring about a chemical change. The necessary conditions are:
1.A minimum amount of energy needed to initiate a reaction, called the activation energy, should be supplied in the form of heat,
light or electric current. In a chemical change the reactants combine to form new products. For this process it is necessary to
break the old bonds of the reactants and forms fresh bonds in order to give new products. This requires a certain amount of
energy.
2. For the occurrence of any reaction, the molecules or atoms of the reactants must collide with one another, in order to break
old bonds and form new bonds.
3. The speed with which the chemical reaction takes place is called the rate of the chemical reaction. This should be
appreciable, to bring about the change.
4. The rate of a reaction depends on following factors:
- Temperature
- Presence of light
- Presence of catalyst
- Electricity
- Pressure.
- Temperature : Certain chemical reactions do not take place at room temperature but occur readily at a higher temperature. Accordingly, heat is required to start the reaction e.g. fuels like coal and wood only start burning when heated to a certain temperature called its ignition temperature.
- Presence of Light : Some reactions take place only in light and do not take place in dark e.g. photosynthesis in green plants or reaction between H2 and Cl2 to form HCl.
- Presence of a Catalyst : A catalyst is a substance that increases the rate of chemical reaction without itself undergoing any change.Example: Hydrogenation of oils to form fats takes place faster, in presence of nickel.
- Electricity : Certain reactions take place with the help of an electric current.Example: Decomposition of acidulated water to give hydrogen and oxygen gas
-
- Pressure : Some chemical reactions need very high pressure to proceed. For e.g., in the commercial manufacture of ammonia from nitrogen and hydrogen by Haber's process, a pressure of over 200 atmosphere is required, in presence of a catalyst iron and a temperature of 450oC to 500oC.
Below are the examples on chemical changes -
(a) Effect of heat on lead nitrate : Lead nitrate is a white, crystalline solid. When heated, it starts decomposing with a
crackling sound, producing a reddish brown gas called nitrogen dioxide, and a colourless gas, oxygen. A yellow residue of lead
monoxide is left behind in the test tube.
(b) Action of concentrated sulphuric acid on sugar :When concentrated sulphuric acid is added to sugar, it becomes a
black mass of sugar charcoal. The acid removes all the water from the sugar, that is, hydrogen and oxygen and absorbs it
leaving a residue of spongy carbon.
(c) Action of sodium on cold water :
When
a small piece (pea size) of sodium is placed in cold water, it darts
about on the water with a hissing sound and produces hydrogen. The water
left behind, acquires the property of turning red litmus blue. This
shows the presence of a basic substance, which is sodium hydroxide
| Physical Change | Chemical Change |
|---|---|
| No new or different substance is formed. The composition of the substance, that undergoes the change, remains unchanged | Results in the formation of at least one new substance. The constituent particles of the new substance are different from the constituent particles of the original substance |
| It is temporary change and in most cases it can be reversed by the reversal of conditions | It is permanent change and cannot be reversed by mere reversal of conditions |
| No change occurs in the mass of the substances undergoing the change | Mass of the individual substances that undergoes the change, always, either increases or decreases. However, the total mass of all the reactants is equal to the total mass of all the products |
Remember :
Sometimes both changes occur together. For example, when a person eats chocolate and then digests it a physical and a
chemical change takes place. When the person chews the chocolate and breaks it into smaller pieces - it is a physical change.
No new substances have been formed yet.
Once acted upon by saliva and other digestive juices, the chocolate is broken down into other simpler substances, which can be
absorbed by the blood. This is a chemical change.
INDICADORES DE LOGRO 3 PERIODO |
3.1 Compares and contrasts properties and states of matter.
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3.2 Understands physical changes and describes ways matter can undergo physical changes.
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3.3. Understands chemical changes and describes ways matter can undergo chemical changes.
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3.4 Identifies the different forms of energy.
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3.5 Identifies the causes of sound
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3.6 Participates in the Science Fair using scientific skills in processes to do research based upon Life, Physical and Earth Science.
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Coming Up!!!!!!! Science Fair
Date:
The Scientific Method
The scientific method is the process all scientists use to investigate science questions. It involves identifying a problem, learning what is already known about that problem, thinking of a solution or answer (called a hypothesis), doing an experiment to test your hypothesis, and reaching a conclusion based on what you learned. There are five steps to the scientific method. They are:
- Identify a problem.
- Formulate a hypothesis.
- Conduct an experiment-
- Collect data
- Data Analysis
- Conclusion
- Publishing/Display
The scientific method is not mysterious or difficult, although you can use it to work through some difficult problems. So before you even begin your project, it is important that you understand the scientific method. Using it to do your project takes some thought, but that’s what science is all about!
Science Fair Project Poster
Science fair project posters typically consist of three columns of text and images.
Here's an example of how you can organize a science fair project poster to clearly display your use of the scientific method for your project.
· Title
The title should be an accurate description of the project. The title is usually centered at the top of the poster.
The title should be an accurate description of the project. The title is usually centered at the top of the poster.
· Pictures/Drawings
Try to include color photographs or drawings of your project, samples from the project, tables, and graphs.
Try to include color photographs or drawings of your project, samples from the project, tables, and graphs.
· Problem/ Question
Sometimes this section is called 'Background'. This section introduces the topic of the project, explains your interest in the project, and states the purpose of the project.
Sometimes this section is called 'Background'. This section introduces the topic of the project, explains your interest in the project, and states the purpose of the project.
· Hypothesis
Explicitly state your hypothesis
Explicitly state your hypothesis
· Materials
List the materials you used in your project
List the materials you used in your project
· Procedure
Describe the procedure that you used to perform the project. If you have a photo or diagram of your project, this is a good place to include it.
· Data and Results
Data and Results are not the same thing. Data refers to the actual numbers or other information you obtained in your project. Data is often presented in a table or graph. The Results section explains what the data means.
Data and Results are not the same thing. Data refers to the actual numbers or other information you obtained in your project. Data is often presented in a table or graph. The Results section explains what the data means.
· Conclusion
The Conclusion focuses on the Hypothesis or Question as it compares to the Data and Results. What was the answer to the question? Was the hypothesis supported? What did you find out from the experiment?
The Conclusion focuses on the Hypothesis or Question as it compares to the Data and Results. What was the answer to the question? Was the hypothesis supported? What did you find out from the experiment?
· References
You may need to cite references or provide a bibliography for your project. Reference may be cited on the posted or printed out and placed below the poster.
You may need to cite references or provide a bibliography for your project. Reference may be cited on the posted or printed out and placed below the poster.
SCIENCE FAIR 2011-2012: AGENDA
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DATE
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A C T I V I T Y
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AUGUST 31, 2011
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Science Teachers will socialize the Science Fair Project in their classes.
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SEPTEMBER 5th - 27th , 2011
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Teachers will guide students toward the science fair project choices.
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OCTOBER 3rd -6th 2011
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First Deadline for choosing a project: Teachers will assess the students’ first choices.
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NOVEMBER 1st – 4th 2011
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Second Deadline for choosing a project: Teachers will assess the students second choices.
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NOVEMBER 8th – 11th , 2011
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Projects must be chosen by this week.
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NOVEMBER 23rd-DECEMBER 13th ,2011
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Students will research their projects themes.
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DECEMBER 14th ,2011
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Deadline for submitting the theoretical framework paper.
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JANUARY 16th , 2012
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Teachers will start to guide the students projects.
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FEBRUARY 29th , 2012
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First Auditorial: Students will present the advances of the project.
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MARCH 30th , 2012
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Second Auditorial: Students will present the advances of the project.
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APRIL 9th-17th , 2012
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Getting everything ready for Science Fair Day.
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APRIL 18th , 2012
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SCIENCE FAIR PROJECT PRESENTATION
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PLANTS AND HOW THEY GROW
- Main parts of plants.
- Why do plants need roots and stems?
- How are plants grouped?
- How do new plants grow?
HOW ANIMALS LIVE
- How are animals grouped?
- How animals grow and change?
- How do adaptations help animals?
- How are animals from the past like today's animals?
More about plants
What do plants need in order to grow?
To grow, plants need water, sunshine for warmth and light, and minerals. The minerals come from the soil and are dissolved in the water and taken up by the plant's roots. Soil containing dead and rotting plant and animal material is the best soil for plants. Worms and other burrowing animals carry mix this material into the soil.
Plants also need the gases carbon dioxide and oxygen which come from the air around them.
Plants use carbon dioxide, water and sun's energy to make its food. This process is called photosynthesis.
As it makes its food the plant produces oxygen. It needs some oxygen but not a lot. The oxygen the plant does not need, leaves the plant through its leaves and goes into the air we breathe.
What are the roots and the stem?
Roots hold the plant in the soil. Roots carry water to the plant's stem. There are 2 main kinds of roots. Fibrous roots are thin roots that spread out through the soil like underground branches.The roots of this tree have spread out above the ground
Tap roots are large thick roots with finer,hairy roots coming off them. Tap roots
store food made in the leaves. It travels down the stem and into the root.Carrots and parsnips are tap roots. People eat many kinds of tap roots.
Roots grow towards water. Stems grow towards light.
What are the leaves?Leaves come in many shapes and sizes. Leaves have veins running through them. The veins carry the water and minerals from the roots and stem through the leaves. Veins also carry food made by the leaves to the rest of the plant.
Green plants have a chemical called chlorophyll in their leaves. This chemical lets the plant use the sun's energy, water and carbon dioxide to make food in the process known as photosynthesis. It is the chlorophyll which makes the leaves green.
Leaves also breathe for the plant. They take in carbon dioxide from the air and give out oxygen.
Leaves are food for animalsMain Parts of Plants
The main parts of a plant are: roots, stem, leaves and flower.
Roots: they hold the plant in the ground, they also take water and minerals from the soil.
Stem: it carries water and minerals from the roots to the leaves.
Leaves: they use the sunlight energy, carbon dioxide, water and minerals to make the plant's own food.
Flowers: they produce seeds. New plants will grow from the seeds.
Roots: they hold the plant in the ground, they also take water and minerals from the soil.
Stem: it carries water and minerals from the roots to the leaves.
Leaves: they use the sunlight energy, carbon dioxide, water and minerals to make the plant's own food.
Flowers: they produce seeds. New plants will grow from the seeds.
SCIENCE FAIR 2011-2012: AGENDA
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DATE
|
A C T I V I T Y
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AUGUST 31, 2011
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Science Teachers will socialize the Science Fair Project in their classes.
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SEPTEMBER 5th - 27th , 2011
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Teachers will guide students toward the science fair project choices.
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OCTOBER 3rd -6th 2011
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First Deadline for choosing a project: Teachers will assess the students’ first choices.
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NOVEMBER 1st – 4th 2011
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Second Deadline for choosing a project: Teachers will assess the students second choices.
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NOVEMBER 8th – 11th , 2011
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Projects must be chosen by this week.
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NOVEMBER 23rd-DECEMBER 13th ,2011
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Students will research their projects themes.
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DECEMBER 14th ,2011
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Deadline for submitting the theoretical framework paper.
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JANUARY 16th , 2012
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Teachers will start to guide the students projects.
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FEBRUARY 29th , 2012
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First Auditorial: Students will present the advances of the project.
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MARCH 30th , 2012
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Second Auditorial: Students will present the advances of the project.
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APRIL 9th-17th , 2012
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Getting everything ready for Science Fair Day.
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APRIL 18th , 2012
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SCIENCE FAIR PROJECT PRESENTATION
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