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PHYSICS AND CHEMISTRY

THE SCIENTIFIC METHOD


The Scientific Method is a way to ask and answer questions about the world in a logical way. There are various versions of the scientific method floating around out there, but I think these six steps are classics. Ask a question, make observations, form a hypothesis, design and conduct an experiment, analyze your data, and draw a conclusion. The steps can be repeated as needed, and using the scientific method is a great way to learn about the world!



 MATERIALS

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Metric System Conversions Song
Magnitudes and units 
Learn how to convert units watching the next video



UNIT 2: PROPERTIES OF MATTER
** EXERCISES PROPERTIES OF MATTER (by Julia Bonilla)

MASS, VOLUME AND DENSITY 
Mass:  mass is the amount of material in an object.  Mass is measured with a scale, usually in grams or kilograms.
Volume: volume is the amount of space occupied by an object. Volume is measured using a graduated cylinder or  is determined by calculation using the dimensions of the object.   Volume is measured  in  cm3, m3, mL and L.
If the object is a square or rectangular block, use the formula   V = L x W x H to calculate volume. If the object is cylindrical, use formula V=πr2h to calculate volume. The volume enclosed by a sphere is given by the formula V=4/3πr3.

If the substance is a liquid, just measure its volume with a graduated cylinder.
For irregular-shaped objects: Use the method known as displacement.  Fill a graduated cylinder or a container with a scale with a set amount of water.  Record the reading ( ie 50 mL).  Carefully add the irregular-shaped object to the cylinder.  Record the new reading ( ie 53 mL) and subtract that from the reading of the water only. The volume of the irregular-shaped object must be 3 mL.



Density is the ratio of mass of an object to its volume. You can think of it as how many particles of a substance are packed into a certain amount of space. If the particles are packed tightly together, the density would be greater than if they are loosely packed with a lot of empty space around them.
Density is determined by measuring the mass of an object, and measuring the volume, then dividing the two. Mass is usually measured in grams (g) and volume in millilitres (ml).
Density is a characteristic property of pure substances; it always be the same under a given set of conditions. Example: density of water at 25ºC is 1g/ml.
Objects with lower densities tend to float (cork floats in water because its density is 0,25 g/ml. Objects with higher densities tend to sink (iron sinks in water because its density is 7,87 g/ml)

ARCHIMEDES AND THE GOLD CROWN
1.- WHERE DOES THIS STORY TAKE PLACE?
2.- WHY WAS THE KING WORRIED?
3.- WHAT WAS THE FIRST IDEA OF ARCHIMEDES?
4.- WHAT IS DENSITY?
5.- WHAT IS THE DENSITY OF THE GOLD?
6.- HOW CAN WE CALCULATE THE DENSITY?
7.- WHAT DID ARCHIMEDES REALIZE?
8.- HOW CAN WE DO THE SAME THAN ARCHIMEDES IN THE LAB?
9.- WHAT WAS ARCHIMEDES SHOUTING?
10.- WAS THE DENSITY RIGHT AT THE END OF THE STORY?



VERNIER CALIPER SIMULATOR
*HOW TO CALCULATE VOLUME AND DENSITY 
* MASS, VOLUME AND DENSITY QUIZ 
* DENSITY PROBLEMS 1
* DENSITY PROBLEMS 2
* DENSITY PRACTICE PROBLEMS WORKSHEET
Calculate:
a) The density of a cube of 200 g and a side of 6 cm. 
b) The mass of a sphere with a radio of 8’5 cm and a density of 6 ́5 kg/l. 
c) The volume of 44 ́5 g of a substance with a density of 7 kg/l. 
d) The density of a box of 890 g and dimensions 6 ́4 cm x 7 ́3 cm x 9 ́2 cm. 
e) The volume of 340 g of a body with a density of 2 ́43 kg/l. 
f) The mass of a cylinder with a radius of 5 cm, a height of 40 cm and a density of 3 ́2 kg/l. 
Solution:a) 0 ́926 g/cm3 b) 16 ́7 kg c) 6 ́36 cm3 d) 2 ́07 g/cm3 e) 140 cm3 f) 10 ́1 kg  
STATES OF MATTER
Matter is all around us. Anything we look at, from hard rocks or the deep blue sea to the invisible air, can be found in three states: solid, liquid or gaseous.
As you can see, all liquids and gases change their shape according to the container holding them. However, only gases take up the entire volume of the container they are in. 
Changes of state are physycal changes in matter. They are reversible changes that do not involve changes in matter´s chemical makeup or chemical properties. Common changes of state include melting, freezing, sublimation, deposition, condensation and vaporization. These changes are shown on figure below:


Kinetic Particle Theory states:
 Matter is composed of particles (atoms, molecules or ions) that are in some way attracted to each other.
 These particles are in constant motion. As the temperature rises, the speed of the particles increases.
**THE KINETIC THEORY
** THE KINETC THEORY AT A GLANCE

EXERCISES KINETIC THEORY

1.- Imagine you leave on a table a glass with four ice cubes inside. Describe what would happen over the time. If you put a thermometer inside, can you explain which temperature it would measure during the process?

2. Explain, using the Kinetic Theory, what is pressure and what is temperature. What happens to pressure if temperature increases? Why?

3. Does always 1 kg of iron occupy the same volume? And 1 kg of oil? And 1 kg of air? Explain the answers taking in mind the Kinetic-Molecular Theory.

4. Complete the sentences using the following words: More, vibrate, far, particles, movement, vigorously, gas, more, gas, solid, volume, quickly, faster (2), expands, liquid.In a solid ………………………………..are closed together. They are in fixed positions but they can ……………………….. When a solid is heated the particles vibrate more…………… …so they take up …………… space.The particles in a ………………….. are quite close together but they can move one from each other. This means that liquids have a definite ……………………… but not a fixed shape. When a liquid is heated, particles in the liquid move …………..In a gas, particles are very ……….  apart.  They are in constant ………………….

* HOW TO READ A HEATING CURVE

CLASSIFICATION OF MATTER: ELEMENTS, COMPOUNDS AND MIXTURES
** EXERCISES ABOUT MIXTURES (By Julia Bonilla)
ELEMENTS AND COMPOUNDS (PURE SUBSTANCES).
Any sample of matter that has the same physical and chemical properties throughout the sample is called a substance. There are two types of substances. A substance that cannot be broken down into chemically simpler components is an ELEMENT. The smallest part of an element that maintains the identity of that element is called an atom. Aluminum, which is used in soda cans, is an element. A substance that can be broken down into chemically simpler components (because it has more than one element) is a COMPOUND. The smallest part of a compound that maintains the identity of that compound is called a molecule. Molecules are composed of atoms.
MIXTURES
A material composed of two or more substances is a mixture. HETEROGENEOUS MIXTURES: Each component can easily be distinguished by the naked eye. Their
properties and composition vary from one part to another of the same system. The components can be separated by mechanical methods ( filtration, decantation, centrifugation, magnetic separation, etc...). HOMOGENEOUS MIXTURES (or solutions) The size of the particles is very small. They cannot be
distinguished visually (neither naked eye or by microscope). Their properties and composition are uniform. The components are only separated by methods that involve changes of state, like evaporation, crystallisation, distillation,
etc...

EXERCISES
  1. Does each statement refer to a chemical property or a physical property?
    1. Balsa is a very light wood.
    2. If held in a flame, magnesium metal burns in air.
    3. Mercury has a density of 13.6 g/mL.
    4. Human blood is red.
  2. Does each statement refer to a chemical property or a physical property?
    1. The elements sodium and chlorine can combine to make table salt.
    2. The metal tungsten does not melt until its temperature exceeds 3,000°C.
    3. The ingestion of ethyl alcohol can lead to disorientation and confusion.
    4. The boiling point of isopropyl alcohol, which is used to sterilize cuts and scrapes, is lower than the boiling point of water.
  3. Define element. How does it differ from a compound?
  4. Define compound. How does it differ from an element?
  5. Give two examples of a heterogeneous mixture.
  6. Give two examples of a homogeneous mixture.
  7. Identify each substance as an element, a compound, a heterogeneous mixture, or a solution.
    1. xenon, a substance that cannot be broken down into chemically simpler components
    2. blood, a substance composed of several types of cells suspended in a salty solution called plasma
    3. water, a substance composed of hydrogen and oxygen
  8. Identify each substance as an element, a compound, a heterogeneous mixture, or a solution.
    1. sugar, a substance composed of carbon, hydrogen, and oxygen
    2. hydrogen, the simplest chemical substance
    3. dirt, a combination of rocks and decaying plant matter
  9. Identify each substance as an element, a compound, a heterogeneous mixture, or a solution.
    1. air, primarily a mixture of nitrogen and oxygen
    2. ringer’s lactate, a standard fluid used in medicine that contains salt, potassium, and lactate compounds all dissolved in sterile water
    3. tartaric acid, a substance composed of carbon, hydrogen, and oxygen
  10. Identify each material as an element, a compound, a heterogeneous mixture, or a solution.
    1. equal portions of salt and sand placed in a beaker and shaken up
    2. a combination of beeswax dissolved in liquid hexane
    3. hydrogen peroxide, a substance composed of hydrogen and oxygen
  11. What word describes each phase change?
    1. solid to liquid
    2. liquid to gas
    3. solid to gas
  12. What word describes each phase change?
    1. liquid to solid
    2. gas to liquid
    3. gas to solid
*PURE SUBSTANCES AND MIXTURES
*DISTILLATION
*CLASSIFICATION OF MATTER 
CONCENTRATION OF SOLUTIONS
There are several ways to express concentration. These  include:


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UNIT 1: SCIENCE AND MEASURE
*LAB EQUIPMENT1
*LAB EQUPMENT2
*QUIZ
**EXERCISES UNIT 1 

UNIT 2: GASES AND SOLUTIONS
I GASES
 *GAS LAWS VIDEOS
*FIRST: BOYLE´S LAW
*SECOND: CHARLES´S LAW 
*THIRD: GAY-LUSSAC´S LAW
*SUMMARY OF GASEOUS STATE 
*MATERIAL TO STUDY AT HOME*

*BOYLE´S LAW PROBLEMS 
*CHARLES´S LAW PROBLEMS
*GAY-LUSSAC´S LAW PROBLEMS 
*COMBINED GAS LAW PROBLEMS (WITH THE SOLUTIONS) 
Boyle's Law Concept Questions
Gas Laws Review Quiz

 II SOLUTIONS ARE MIXTURES  BUT, ALWAYS THAT WE MIX SUBSTANCES MIXTURES ARE OBTAINED ?
When you mix two or more different substances, there may be two different situations: a mixture or a chemical reaction. In a mixture the substances continue being the same ones. The molecular kinetic theory explains the physical changes in mixtures  supposing that molecules move more or less quickly and they come close together or move away.
In chemical changes the substances that there are at the beginning disappear and in their place appear new ones. The molecular kinetic theory explains chemical changes supposing that molecules break when they hit to each other and the resulting atoms combine forming other molecules. 

* HOMOGENEUS MIXTURES OR SOLUTIONS 
* TYPES OF SOLUTIONS.SOLUBILITY
* MORE CONCENTRATION EXERCISES WITH SOLUTION 
* MIXTURES AND SOLUTIONS VS CHEMICAL REACTIONS
THE MOLE
To start with, you must be very clear about what exactly does a mole represent. The mole is the unit of measurement in the International System of Units (SI) for amount of substance. 1 mole in quantity, that implies that the matter under consideration contains exactly 6.022 * 1023 number of particles (atoms, molecules, ions, electrons or any other elementary entities).
Though mole is defined as a number but it’s not limited to that in calculations. It has various other equivalent definitions with the only difference from each other being that they define mole for different states of matter and at different conditions.
UNIT 3: ATOMS and COMPOUNDS
Taken from this LINK
THE STANDAR MODELOF PARTICLE PHYSICS


2.- ORIGINS OF ELEMENTAL NAMES
3.- THE PERIODIC TABLE SONG

 
*READING COMPREHENSION: ATOMIC HISTORY
* BUILD AN ATOM 
*CHEMICAL BOND1
*CHEMICAL BOND2  
*DIFFERENT MATERIALS TO STUDY CHEMICAL BONDS
*NOMENCLATURE OF INORGANIC CHEMISTRY

* WORKSHEET 1: ATOMI´S STRUCTURE

UNIT 4: CHEMICAL REACTIONS 
* STOICHOMETRY PRACTICE PROBLEMS
* CHEMICAL REACTIONS AND EXERCISES 
* CHEMICAL REACTIONS EXERCISES 
* CONSERVATION OF MASS WORKSHEET

PHYSICS
*KINEMATICS AND DYNAMICS ACTIVITIES


SCIENCE IN ENGLISH. ARE YOU READY? (After read it, write what you think about it)

Top Reasons Why Students Fail Chemistry

Avoiding Failure in Chemistry

By

Are you taking a chemistry class? Are you worried you might not pass? Chemistry is a subject many students prefer to avoid, even if they have an interest in science, because of its reputation for lowering grade point averages. However, it isn't as bad as it seems, especially if you avoid these common mistakes.

1. Procrastinating

Never do today what you can put off until tomorrow, right? Wrong! The first few days in a chemistry class may be very easy and could lull you into a false sense of security. Don't put off doing homework or studying until halfway through the class. Mastering chemistry requires you to build concept upon concept. If you miss the basics, you'll get yourself into trouble. Pace yourself. Set aside a small segment of time each day for chemistry. It will help you to gain long-term mastery. Don't cram.

2. Insufficient Math Preparation

Don't go into chemistry until you understand the basics of algebra. Geometry helps, too. You will need to be able to perform unit conversions. Expect to work chemistry problems on a daily basis. Don't rely too much on a calculator. Chemistry and physics use math as an essential tool.

3. Not Getting or Reading the Text

Yes, there are classes in which the text is optional or completely useless. This isn't one of those classes. Get the text. Read it! Ditto for any required lab manuals. Even if the lectures are fantastic, you'll need the book for the homework assignments. A study guide may be of limited use, but the basic text is a must-have.

4. Psyching Yourself Out

I think I can, I think I can... you have to have a positive attitude toward chemistry. If you truly believe you will fail you may be setting yourself up for a self-fulfilling prophecy. If you have prepared yourself for the class, you have to believe that you can be successful. Also, it's easier to study a topic you like than one you hate. Don't hate chemistry. Make your peace with it and master it.

5. Not Doing Your Own Work

Study guides and books with worked answers in the back are great, right? Yes, but only if you use them for help and not as an easy way to get your homework done. Don't let a book or classmates do your work for you. They won't be available during the tests, which will count for a big portion of your grade.