PHYSICS AND CHEMISTRY 2º ESO

CONTENIDOS DE LA ASIGNATURA
BLOQUE 1: La actividad científica.
BLOQUE 2: Propiedades de la materia.
BLOQUE 3: Clasificación de la materia. Disoluciones.
BLOQUE 4: El átomo.
BLOQUE 5: Los cambios.
BLOQUE 6: Las fuerzas.
BLOQUE 7: La energía.

BLOQUE 1:  LA ACTIVIDAD CIENTÍFICA
SCIENTIFIC ACTIVITY

**SUMMARY UNIT 1**
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 there, but I think these six steps are classics: ask a question, make observations, form a hypothesis, design an experiment, analyze your data, draw a conclusion and communicate results. The stpes can be repeated as needed, and using the scientific method is a great way to learn about the world!!
5.- TO STUDY THE UNIT 1 IN ENGLISH
13.- METRIC SYSTEM CONVERSIONS SONG
14.- MAGNITUDES AND UNITS 

MORE ...
BLOQUE 2:  PROPIEDADES DE LA MATERIA
PROPERTIES OF MATTER

**MATTER AND ITS PROPERTIES (I recommend it to you)
MASA, VOLUMEN Y DENSIDAD
MASS, VOLUME AND DENSITY 
Mass:  mass is the amount of materia in an object. The smallest unit of matter is the atom. Atoms can combine to form molecules. An ion is a charged atom or molecule. 
Mass is measured with a scale, usually in grams or kilograms.
Do not confuse mass and weight.

 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 or a pipet.
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
ARQUIMEDES Y LA CORONA DE ORO
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. KINETIC THEORY
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.

* HEATING CURVE
- What are Heating and Cooling Curves?
* HOW TO READ A HEATING CURVE

BLOQUE CLASIFICACIÓN DE LA MATERIA: ELEMENTOS, COMPUESTOS Y MEZCLAS. MÉTODOS DE SEPARACIÓN
CLASSIFICATION OF MATTER: ELEMENTS, COMPOUNDS AND MIXTURES. SEPARATION TECHNIQUES

VIDEO TO START WITH

*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...
ACTIVITIES CLASSIFICATION OF MATTER
 *SEPARATION TECHNIQUES
DECANTATION
FILTRATION
EVAPORATION AND CRYSTALLISATION

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
*PURE SUBSTANCES AND MIXTURES
*DISTILLATION
*CLASSIFICATION OF MATTER 
CONCENTRACIÓN DE DISOLUCIONES
CONCENTRATION OF SOLUTIONS

A solution is a homogeneous mixture of two or more components. Solution have two components, one is solvent and the other is solute. 
Solvent: is the component that disolves the solute. Generally, solvent is present in major porprotion compared to solute.
Solute: is the component that is dissolved in the solvent. The amount of solute is lesser than the solvent.
The solute and solvent can be any state of matter (solid, liquid and gas).
Concentration of a solution is the amount of solute in a given amount of solution. Depending upon the proportion of solute, a solution can be diluted, concentrated or saturated.
There are several ways to express concentration. These  include:

EXERCISES
1. If 30.0 grams of AgNO3 are dissolved in 275 grams of water, what is the concentration of the silver nitrate by mass percent?

2. How many grams of MgF2 are present in 100 g of a 20.0% MgF2 in water solution?

3. How many grams of water are present in the solution in question 2?

4. The density of a 30% by mass solution of NaOH in water is 1.33 g/mL. How many grams of NaOH are required to prepare 500 mL of this solution?

5. The density of pure water is 1 g/mL. What is the concentration gy percent mass of a solution prepared by dissolving 85 grams of NaOH in 750 mL of water?

6. A solution is prepared by dissolving 66 g of acetone in 146 grams of water. The density of the acetone is 0,78 g/ml and the density of the solution is 0.926 g/mL. What is the percent concentration of acetone by volume?

7. A 35.4% solution of H3PO4 in water has a density of 1.20 g/mL. How many grams of phosphoric acid are present in 300 mL of this solution? 

* SOLUTIONS WORKSHEET. CALCULATE CONCENTRATION IN % by mass, % by volume and g/L
BLOQUE EL ÁTOMO
THE ATOM
*WHAT IS AN ATOM?
The idea of atoms was invented by two Greek philosophers, Democritus and Leucippus in the fifth century BC. The Greek word ατoμoν (atom) means indivisible because they believed that atoms could not be broken into smaller pieces.

An early model of the atom was developed by the physicist Ernest Rutherford in 1911. He was the first to suggest that atoms are like miniature solar systems, except that the atractive forcé is not caused by gravity, but by opposing electrical charges. In the so-called Rutherford atom, electrons orbit the nucleus in circular paths. Rutherford also proposed that atoms have a small dense center filled with positive charges. He named this cernter nucleus. 


- HISTORY OF THE ATOM WORKSHEET
- VIDEO ¿QUÉ ES UN ÁTOMO? 
- VIDEO THE ATOM THROUGH TIME 
EXERCISES

1.- Fill in the blanks with the words: BREAK-CHARGE-ELECTRONS-ENERGY-MASS- NEGATIVE-NUCLEUS- ORBIT-PROTONS-SHARED-SHELLS
The _____________ is in the middle of an atom . It is made up of _____________ and neutrons. It has almost all of an atom’s _____________. _____________ fly around in an atom very quickly. They move in paths called _____________. The inner path can hold only two electrons, the outer paths up to 32. Each proton has a positive electrical _____________. Electrons have a _____________ charge. The _____________ of the nucleus keeps the electrons in its _____________. But they often want to _____________ away from the atom. Sometimes one electron is _____________ by two different atoms.

2.- True or false?
-Electrons do not have an electric charge.
-Electrons that move around in the inner shells travel fast.
-The atomic number tells you how many protons an atom has.
-All elements can be found in nature.
-Sometimes elements have more neutrons than protons.
-Ions are atoms that gain or lose electrons.
-When you split an atom a lot of energy is created.
-Compounds are atoms that have the same nucleus.
-Organic compounds always have hydrogen atoms in them.
-Isotopes of an element always have the same number of protons.
*ATOMIC NUMBER, MASS NUMBER, ISOTOPES WORKSHEET WITH SOLUTIONS

MATERIALS

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.