Science: febrero 2013

Finding the density of two coins on the virtual lab on Vermont School and cleaning a rare, valuable coin and chemical compositions.

Simón Galindo ,7-A

Vermont School

Finding the density of two coins on the virtual lab on Vermont School and cleaning a rare, valuable coin and chemical compositions.

Colegio Gimnasio Vermont Medellín

Biology

Stage Grade

Simón Galindo Zuluaga

Medellín, Antioquia

20/02/2013

Finding the density of two coins on the virtual lab on Vermont School and cleaning a rare, valuable coin and chemical compositions.

Introduction….

In this Apa Template we are going to find the density of two coins. We are going to know more about the chemical and physical properties,processes and changes. Also, we are going to know the Atomic Model through history and learn: How you can reach the density of an object?Also we are going to know why cleaning rare coins is a bad idea!!!

Theoretical Background

1Physical and chemical properties

1.1Physical property: Is a characteristic of a substance that does not involve a chemical change, such as density, color, or hardness.

1.2Chemical property: Is a property of matter that describes a substance's ability to participate in chemical reactions.

2.Chemical Reaction

A reaction in which one or more substances are converted into different substances. The reactants are the starting materials in a chemical reaction. The products are the substances that are formed by a chemical reaction.

3.Physical and chemical

A physical change is a change of matter from one form to another without a change in chemical properties.

A chemical change is a change that occurs when one or more substances change into entirely new substances with different properties.

4.Physical Processes

4.1Distillation

Distillation is a water purification process that uses a heat source to vaporize water and separate it from contaminants. The water is heated at 100 degrees and evaporated, vapors go to the cooler, cool and condense, passing again to the liquid state.

4.2Evaporation

Is the process in which water converts in vapor, by first boiling and then changing state? The temperature has to raise the boiling point (100ºC) because it takes more time to evaporate, because affect the mass, density and volume of the water.

4.3Filtration

Consists on separate solid residues or matter from water by passing the material at a low speed, permitting liquid to pass and leaving residues in the filter.

5.Chemical Process

5.1Combustion:

Combustion reactions always involve molecular oxygen O2. Anytime anything burns (in the usual sense), it is a combustion reaction. Combustion reactions are almost always exothermic (i.e., they give off heat). For example when wood burns, it must do so in the presence of O2 and a lot of heat is produced.

5.2Neutralization:

“Neutralization reaction refers to acid and base reaction producing salt and water. The equivalent amounts of acid react with base to form equivalent amounts of salt and water. When the reaction is complete, acid and base are said to neutralize each other. Since water is produced, neutralization reaction is also referred as “water forming reaction”.

5.3Electrolysis:

“Process by which electric current is passed through a substance to effect a chemical change. The chemical change is one in which the substance loses or gains an electron (oxidation or reduction).The process is carried out in an electrolytic cell, an apparatus consisting of positive and negative electrodes held apart and dipped into a solution containing positively and negatively charged ions”

5.4Corrosion:

“Is the loss of metallic properties of a metal as the metal reacts with the atmosphere or water. e.g. strength, luster or shine and electrical conductivity. Rust is brownish red in color and is formed from the corrosion of iron. Other metals like copper and aluminum also corrode or weaken. For corrosion to occur both water and oxygen need to be present”

6.Density

Density is a physical property of matter, as each element and compound has a unique density associated with it. Density defined in a qualitative manner as the measure of the relative "heaviness" of objects with a constant volume.

Equation:

7.Matter

Matter is all surrounding you, that have a volume, weight and mass.

8.Volume

Volume is the amount of space taken up or occupied by an object..

Equation: Mass/Density.

9.Weight

Gravity acting over all the matter and energy in our planet is call weight.

10.Mass

Mass is the amount of matter that something is made of.

Equation: Density X Volume.

11.Energy

All surrounding you, that don’t have volume, weight and mass.

Equations 1: 9.8 m/s=Per second

Equation 2:

12.Atom

Atom is the name that means ”Without division”.

13,Atomic Models

13.1John Dalton :

Dalton proposed a modern atomic model based on experimentation not on pure reason, he also said:

1. All matter is made of atoms.

2. Atoms of an element are identical.

3. Each element has different atoms.

4. Atoms of different elements combine in constant ratios to form compounds.

5. Atoms are rearranged in reactions.

13.2Ernest Rutherford:

Most particles passed through. So, atoms are mostly empty. Some positive α-particles deflected or bounced back! Thus, a “nucleus” is positive & holds most of an atom’s mass.

13.3BÖHR

Electrons orbit the nucleus in “shells” Electrons can be bumped up to a higher shell if hit by an electron or a photon of light , the Bohr model was a one-dimensional model that used one quantum number to describe the distribution of electrons in the atom.

There are 2 types of spectra: continuous spectra & line spectra. It’s when electrons fall back down that they release a photon. These jumps down from “shell” to “shell” account for the line spectra seen in gas discharge tubes (through spectroscopes).

13.4 J.J THOMPSON:

He discover that electrons are negative charged part of every atom, he also discovered that atoms are positive and that are spread together in the atom, like a cloud.

13.5 ERWIN SCHRÖDINGER:

Schrödinger combined the equations for the behavior of waves with the de Broglie equation to generate a mathematical model for the distribution of electrons in an atom, this models contains Mathematical Equation Know as wave function that can know the behavior of electrons , this model based on waves that why this model is called Wave Function.

1. Objectives

a) Learn more about chemical and physical Properties, Changes and processes.

b) Know more about different equations to find Density, Mass and Volume.

c) Find the coin with most density.

d) Have fun with this new activity.

e) See why cleaning rare coins is a bad idea.

2. Materials and Reactives

Materials and Reactives in both stages:

Materials	Reactives
Virtual Coins.	Virtual Water
Computer.
Balance.
Graduate.
Virtual gloves, virtual glasses and virtual lab coat.
Calculator

3. Procedure

Stage 1

1. Click on the coin A and put it on the balance for finds its mass.

2. Copy the mass.

3. Measure the water level on the graduate.

4. Then put coin A and copy he last volume.

5. Do the same with coin B.

6. Make the procedure of density.

Stage 2

1.Click on the lab coat,glosses and safety glosses,Then ,click Enter.

2.Move your pointer over a labeled cointainer to learn more about the cleaning substance.

3.Click the first coin on the left side of the screen.Carefully observe the way the coin looks before cleaning.

4.Click Continue to begin the cleaning process.

5.Carefully observe the coin after the cleaning takes place, and then click Continue.

6.You can use the Close-up button on the left at any time to see how the coin looked before cleaning.Use the Close-up button on the right to see how a coin looks after a cleaning.

7.Repeat step 3.6 for the second and third coins.

8.Answer the questions,and then Evaluate.

5. Observations and Results

Results

Stage 1

Samples	Mass (g)	Water level (ML)	Water level(ML)	Volume(cm3)
Coin A	26.7(g)	50.0	52.6 (ML)	2.6 (cm3)
Coin B	26.3(g)	50.0	52.8(ML)	2.8(cm3)