Dialogue Of The Teacher And Students About Chemistry

Time Chemical Class

Teacher    :  Good morning students.

Students  : Morning Mrs.

Teacher    : How are you today, are you ready to study chemistry?

Students  : Yes, we are ready Mrs.

Teacher  : Well today we will discuss the topic of radioactive elements. Does anyone know what a radioactive element is?

Windra : The radioactive element is an element or substance whose nucleus is unstable.

Teacher : Yes that's true Windra, is there anything you want to add?

Intan : The radioactive element is an element that spontaneously emits radiation, Mrs.

Teacher : Okay, Windra and Intan answer is good enough. So, the radioactive element is an element whose atomic nucleus is unstable and spontaneously emits radiation. The radioactive elements are diverse, there are gamma rays, beta rays and alpha rays.

Intan  : Mrs, what is gamma rays, alpha and beta?

Teacher  : Can anyone answer the question from Intan?

Windra  : I know Mrs what is alpha rays. Alpha rays are radioactive rays that have charged particles of +2 and their atomic mass is 4.

Teacher :  Very good, Windra. Here Mrs will explain it. Alpha rays are radioactive rays that have charged particles of +2 and their atomic mass is 4. whereas the beta beam is a beam of light consisting of negatively charged particles that are identical to electrons, and gamma rays are uncharged electromagnetic radiation emitted by the nucleus Which are in energetic condition.

Windra : Then is there a function of each of these rays Mrs?

Teacher: Yes, of course there is Windra, for Sinar Alfa, particles of alpha rays are very easy to stop, usually it is used to detect the presence of smoke. Closed sources of alpha-ray particles from the americium will send alpha particles into the air. When there is smoke, the particles will be blocked and signal to the transmitter alarm. Sinar Beta Sinar beta is widely used to control the production lines of paper, plastic or steel sheeting. The gamma rays used are emitted with the flow of water in the pipe to find out any leakage of the pipe. Gamma rays of a certain intensity can also be used as radiotherapy to kill cancer cells.

Intan   : So the radioactive rays are of much use in certain areas of the ya ya Mrs? I want to ask Mrs, is there any negative impact of using radioactive rays?

Teacher : of course there is a negative impact of Intan, Radiation of radioactive substances can shorten the human life. This is because the radioactive substances can cause damage to body tissues and reduce body immunity. Radiation of radioactive substances against the genital glands can lead to infertility and genetic mutations in offspring. Radiation of radioactive substances can lead to the occurrence of white blood cell division, resulting in leukemia disease. Radiation of radioactive substances can cause localized somatic damage with signs of skin damage, damage to blood-forming cells, and damage to the nervous system. Environmental pollution caused by radioactive dust due to the explosion of atomic reactors and atomic bombs, such as 90 Sr causes bone cancer. Effects and Effects caused by radiation of radioactive substances in humans are usually Dizziness, decreased appetite or loss, Diarrhea, heat or fever, Weight loss, Blood cancer or leukemia, Increased heart rate or pulse. Well that was something about radioactive rays, can anyone deduce our learning today?

Windra : I Mrs, The use of radioisotopes is very helpful to humans in various areas of life as mentioned earlier, but the negative impact of its use is also a lot of Mrs, one of them can cause health problems in humans are dizziness, weight loss, fever, and still much more.

Intan : Radioactive rays there are three types of Mrs,  alpha, beta and gamma rays. For alpha rays are radioactive rays that have charged particles of +2 and their atomic mass is 4. Whereas the beta beam is a beam of light consisting of negatively charged particles identical to electrons, and gamma rays are the uncharged electromagnetic radiation emitted by Nuclei that are in energetic conditions.

Teacher : Okay, the conclusion is pretty good, since our time is up, we continue next week, for further material please you learn at home.  See  you  next  week.

CAUSE AND EFFECT CHEMICAL REACTION

CAUSE AND EFFECT OF RAIN ACID

Naturally, acid rain has a degree of acidity (pH) slightly below 6 because carbon dioxide gas (CO2) reacts with water vapor (H2o) in the air to create acid rain. This acid rain is very good in terms of helping dissolve minerals, but become a metal enemy.

Understanding acid rain on this day widespread. Why? Because it also involves nitrogen and sulfur gas (sulfur) in the air which then reacts with oxygen to form nitrogen dioxide (NO2) and sulfur dioxide (SO2).

The gase then reacts again with H2O (water vapor) to form nitric and acidic acids that eventually condense; Forming clouds that lower acid rain.

There are various opinions that state about the factors causing acid rain.

A.   Factors Cause Acid Rain

Ø  Basically This acid rain is caused by two air pollutants ie, SO2 or Sulfur Dioxide and NOx or Okside Nitrogen both of which are created / generated through combustion. However, about 50% of the Sulfur Dioxide (SO2) that exists in the Earth's atmosphere is created naturally, that is, coming from forest fires or volcanic eruptions. While the other 50% is the result of human activities, for example due to smelting metal, burning BBF, and power plants. Petroleum generally contains 0.4 to 5% of the coal and sulfur is between 0.1% to 3%. When the BBF is burned, the sulfur with a concentration of 0.1% -3% is oxidized, and there is sulfur dioxide / sulfur dioxide (SO2) and loose in the air. The sulfur / sulfur oxide is then converted to sulfuric acid (Soemarwoto O, 1992).

Ø  Acid rain is caused due to the formation of acid in the air is triggered from the meeting of acid-forming gases with water vapor. Usually it happens because of pollution / air contamination around the factory. Gases that are often the cause of acid rain include:

1.   Carbon monoxide (CO) and Carbon dioxide (CO2)

Both gases come from motor vehicle pollution, combustion products, etc., which when the two gases meet the water vapor (H2O) will form carbonic acid (H2CO3) which is classified as weak acid.

2.  Hydrogen sulfide (H2S) and Sulfur dioxide (SO2)

Both gas comes from heating sulfur / burning. Generally these gases are found in heavy industrial areas, which when they meet with water vapor (H2O) will form sulfuric acid (H2SO4) which is classified as strong acid. The acid acid rain rate is calculated from the concentration of acid in the air, which is indirectly, meaning also calculated by the degree of pollution / air pollution in the air. In normal status, in fact, CO2 in the air causes the rain we normally enjoy it is acidic. But the pH is not far below 7. In contrast to areas with severe pollution / air contamination, the degree of acidity (pH) is much lower. There is a close and direct connection between corrosion and acid rain. Corrosion, is the process of weathering metal by substances belonging to oxidizer. And acid, is a substance that can easily oxidize metals. So in the event of acid rain, there will certainly be corrosion in the metals affected by acid rain.

B.     Effect Of Acid Rain

Acid content in rainfall causes rain to have the same properties as acid solutions in general. The acid present in acid rain is a strong acid. After learning about the nature of acids, can you estimate what impacts can be caused if acid rain occurs in a region?

Naturally the rain is acidic with a pH between 5.6 to 6.2 because of the CO2 content in the air. CO2 in the air reacts with water vapor to form a weak acid that is carbonic acid (H2CO3). However, the acidity caused by H2CO3 is considered normal because this type of acid is useful to help dissolve the soil minerals needed by plants and animals. Unlike the content of H2SO4 and HNO3 which is a strong acid that can damage the living tissue. Here are some of the impacts of acid rain on the environment and living things:

Ø      Acid rain with high acidity levels can cause respiratory distress in humans. The fog containing sulfuric acid together with the air inhaled and into the human respiratory tract can damage the lungs.

Ø  Causes corrosion and damage to buildings

Acid rain can accelerate the corrosion process. The corrosion process can occur on some materials of metal. Corrosion is the event of metal destruction caused by chemical reactions between metals and the environment that produce unwanted products. Such environments may be acids, bases, oxygen in air, oxygen in water, or other chemicals. This unwanted product is rust.

Ø  Plants wither, dry and die

Soluble acid rain along with nutrients in the soil will sweep the nutrients in the soil before the plants could use it to grow. Toxic chemicals such as aluminum will also be released and mixed with nutrients. If these nutrients are absorbed by plants will inhibit the growth and accelerate the leaves fall, then the plant will be attacked by disease, drought, and die 4. Damaging aquatic ecosystems. Acid rain falling on the lake will increase the acidity of the lake. The increased acidity of the lake causes some species of aquatic biota to die because they are unable to survive in acidic environments. Although there are some species that can survive but because the food chain is disturbed then the species can experience death as well.

Chemistry Vocabulary

1.      Acid - There are several ways to define an acid, but they include any chemical that gives off protons or H⁺ in water. Acids have a pH less than 7. They turn the pH indicator phenophthalein colorless and turn litmus paper red.

2.     Alcohol - An alcohol is any organic molecule that has an -OH group.

3.     Aldehyde - An aldehyde is any organic molecule that has a -COH group.

4.     Alkane - An alkane is an organic molecule that only contains single carbon-carbon bonds.

5.     Alkene - An alkene is an organic molecule that contains at least one C=C or carbon-carbon double bond.

6.     Alkyne - An alkyne is an organic molecule that contains at least one carbon-carbon triple bond.

7.     Base - A base is a compound that produces OH^- ions or electrons in water or that accepts protons. An example of a common base is sodium hydroxide, NaOH.

8.     Beta particle - A beta particle is an electron, although the term is used when the electron is emitted in radioactive decay.

9.     Binary compound - A binary compound is one made up of two elements.

10.   Binding energy - Binding energy is the energy that holds protons and neutrons together in the atomic nucleus.

11.    Bond energy - Bond energy is the amount of energy required to break one mole of chemical bonds.

12.   Bond length - Bond length is the average distance between the nuclei of two atoms that share a bond.

13.   Buffer - A liquid that resists change in pH when an acid or base is added. A buffer consists of a weak acid and its conjugate base. An example of a buffer is acetic acid and sodium acetate.

14.   Calorimetry - Calorimetry is the study of heat flow. Calorimetry may be used to find the heat of reaction of two compounds or the heat of combustion of a compound, for example.

15.   Carboxylic acid - A carboxylic acid is an organic molecule containing a -COOH group. An example of a carboxylic acid is acetic acid.

16.   Catalyst - A catalyst is a substance that lowers the activation energy of a reaction or speeds it up without being consumed by the reaction. Enzymes are proteins that act as catalysts for biochemical reactions.

17.   Cathode - A cathode is the electrode which gains electrons or is reduced. In other words, it is where reduction occurs in an electrochemical cell.

18.   Crystal - A crystal is an ordered, repeating three-dimensional pattern of ions, atoms, or molecules. Most crystals are ionic solids, although other forms of crystals exist.

19.   Diffusion - Diffusion is the movement of particles from an area of higher concentration to one of lower concentration.

20.  Dilution - Dilution is when a solvent is added to a solution, making it less concentrated.

21.   Effusion - Effusion is when a gas moves through an opening into a low-pressure container (e.g., is drawn by a vacuum). Effusion occurs more quickly than diffusion because additional molecules aren't in the way.

22.  Electrolysis - Electrolysis is using electricity to break the bonds in a compound to break it apart.

23.  Electrolyte - An electrolyte is an ionic compound that dissolves in water to produce ions, which can conduct electricity. Strong electrolytes completely dissociate in water, while weak electrolytes only partially dissociate or break apart in water.

24.  Family - A family is a group of elements sharing similar properties. It is not necessarily the same thing as an element group. For example, the chalcogens or oxygen family consists of some different elements from the nonmetal group.

25.  Kelvin - Kelvin is a unit of temperature. A Kelvin is equal in size to a degree Celsius, although Kelvin starts from absolute zero. Add 273.15 to a Celsius temperature to get the Kelvin value. Kelvin is not reported with a ° symbol. For example, you would simply write 300K not 300°K.

26.  Ketone - A ketone is a molecule that contains a R-CO-R' functional group. An example of a common ketone is acetone (dimethyl ketone).

27.  Ligand - A ligand is a molecule or ion stuck to the central atom in a complex. Examples of common ligands include water, carbon monoxide, and ammonia.

28.  Mass - Mass is the amount of matter in a substance. It is commonly reported in units of grams.

29.  Nucleon - A nucleon is a particle in the nucleus of an atom (proton or neutron).

30.  Oxidation number The oxidation number is the apparent charge on an atom. For example, the oxidation number of an oxygen atom is -2.

31.   Period - A period is a row (left to right) of the periodic table.

32.  Product - A product is something made as a result of a chemical reaction.

33.  Quantum theory - Quantum theory is the description of energy levels and the predictions about the behavior of atoms at specific energy levels.

34.  Radioactivity - Radioactivity occurs when the atomic nucleus is unstable and breaks apart, releasing energy or radiation.

35.  Strong acid - A strong acid is an acid that completely dissociates in water. An example of a strong acid is hydrochloric acid, HCl, which dissociates into H⁺ and Cl^- in water.

36.  System - A system includes everything you are evaluating in a situation.

37.  Temperature - Temperature is a measure of the average kinetic energy of particles.

38.  Titration - Titration is a procedure in which the concentration of an acid or base is determined by measuring how much base or acid is required to neutralize it.

39.  Unshared electron pair - An unshared electron pair or lone pair refers to two electrons that aren't participating in chemical bonding.

40.  Valence electron - The valence electrons are the atom's outermost electrons.

COMPARE AND CONTRAST

A. Compare
     Tell what is the same about two or more things or identify similarities between subjects.

B. Contrast
    Tell what is the real comparison of an object or explain ways in wich they are different.

C. Double Bubble Maps
     Bubble maps help students define qualities so they begin to write descriptive passages. they focus on using adjactives to discribe the item in the center of the maps.

Example :