Friday, October 18

CHEMISTRY - STATES OF MATTER & PHYSICAL & CHEMICAL CHANGES - MODULE #3 B

SOLID
A solid is a state of matter in which the substance has a definite size and shape. The molecules that make up a solid are very close together and do not move about as they do in liquids and gases.
  • A solid becomes a liquid when it is heated to its melting point. 
    • A few solids change directly from a solid to a gas and this process is called sublimation.
  • Some substances are called semi-solids. They are actually very thick liquids that seem like solids as they move much less than most liquids.
Some of the properties of solids are their 
    • shape, color, hardness, density (thickness), brittleness (how easily it can be smashed or broken into pieces), malleability, ductility, elasticity, tensile strength 
LIQUIDA liquid is a state of matter that has a definite size or volume but not a definite shape. 
  • A liquid takes the shape of the container in which it is held and presses on the container in the same amount in all directions. 
  • The molecules in a liquid are closer together than those in a gas but not as close together as those in a solid. 
  • The molecules in solids are in a fixed position but those in liquids move around more.
  • Although molecules in a liquid hang together through forces called cohesion. 
  • The molecules at the surface of a liquid can also jump off from the liquid into the surrounding air in a process called evaporation
    • The rate of evaporation depends on the humidity of the air, how much of the surface of a liquid is exposed to the air, and the temperature.
Most liquids expand or spread out when heated and contract when cooled. 
  • When a liquid is heated to its boiling point, it changes to a gas. 
  • When a liquid is cooled to its freezing point, it becomes a solid. 
  • The melting point and boiling point are two ways to tell what a liquid is as liquids can differ in these measures. 
    • Heating a mixture can be used to separate out the parts of a mixture.
  • One property of liquids is diffusion. Diffusion is when the movement of a concentration in one part of a liquid that is higher to a part of the substance where the concentration is lower.
  • Liquids are also difficult if not impossible to compress.
  • Liquids also exert buoyancy on other objects placed within the liquid. The amount of buoyancy is equal to the amount of the liquid that is pushed out of place when the object is placed in the liquid.

GAS
A gas is a state of matter in which the substance has no definite shape or volume (size). 
  • Gases take the shape and fill any container in which they are placed. 
  • The molecules in gases move more quickly than those in liquids or solids and are spread out much more than in either liquids or solids.
  • Gases change to liquids or solids if they are cooled or if enough pressure is applied to them. 
    • The cooling of a gas so it becomes a liquid is called condensation
    • If a gas changes directly to a solid, it is called sublimation.
There are several important scientific laws relating to gases. 
  • One is Boyle's Law, named after Robert Boyle. This states that the greater the pressure upon a gas, the smaller the volume that gas will take up and the less the pressure, the greater the volume or space a gas will take up in a closed space. 

PHYSICAL & CHEMICAL CHANGES
There are several differences between a physical and chemical change in matter or substances.
  • A physical change in a substance doesn't change what the substance is. 
  •  In a chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed. 
    • For example, if a piece of paper is cut up into small pieces it still is paper. 
    • This would be a physical change in the shape and size of the paper. 
    • If the same piece of paper is burned, it is broken up into different substances that are not paper.
  • Physical changes can be reversed
  • Chemical changes cannot be reversed with the substance changed back without extraordinary means, if at all. 
    • For example, a cup of water can be frozen when cooled and then can be returned to a liquid form when heated.
If one decided to mix sugar into water to make sugar water, this would be a physical change as the water could be left out to evaporate and the sugar crystals would remain. However, if one made a recipe for a cake with flour, water, sugar and other ingredients and baked them together, it would take extraordinary means to separate the various ingredients out to their original form.
  • When heat is given off in a chemical change or reaction, it is called an exothermic reaction
  •  When heat is absorbed in a chemical change or reaction, it is called an endothermic reaction
The speed at which chemical reactions take place depend on the temperature pressure and how concentrated the substances involved in the chemical reaction are. Sometimes substances called catalysts are used to speed up or help along a chemical reaction.

CHEMISTRY - ATOM QUIZ

PLEASE TAKE QUIZ 
DRAW AN ATOM - notebook paper
  • LABEL THE PARTS OF AN ATOM
Complete Bohr Diagrams
  •  'B' (Boron) atomic number = 5

Complete Lewis Structure

  • 'F' (Florine) atomic number = 9

 
RECORD YOUR RESULTS ON NOTEBOOK PAPER.
NO TALKING
NO NOTES
  1. YOUR NAME
  2. NAME OF QUIZ 
  3. RESULTS

ATOM QUIZ - 10/18

COUGH PROJECT - COMMUNICABLE DISEASES

7 Ways to Stop the Spread of Flu Germs

Unfortunately, you've caught the flu. Help keep from spreading it to your friends and family by following these tips.

A typical flu season can last from October through May, usually peaking in January and February. The single best way to avoid the flu is to get a flu vaccine. But if you or someone in your home is already sick, try to keep the virus from spreading to other family members.
Flu germs spread from person to person through coughing, sneezing and by touching contaminated surfaces and objects. Here are some tips that may help you keep the illness at bay.
Stay home. To get over the flu and to prevent spreading it to others, stay home from work or school while you have flu symptoms. These may include body aches, fever, stuffy or runny nose, cough, headache, tiredness and sore throat. Sometimes vomiting and diarrhea occur, but this is seen more often in children. You should stay home for at least 24 hours after your fever is gone without use of fever-reducing medicine.

Wash your hands frequently, for at least 20 seconds with soap and water. This is one of the most important steps you can take to help stop the spread of germs. Dry your hands with a disposable paper towel. Carry an alcohol-based hand gel, spray or wipes when you are out, in case soap and water aren't available. Wash your hands as soon as possible:
  • After:
  • Sneezing, coughing or blowing your nose
  • Caring for a sick person
  • Using the bathroom
  • Before:
  • Preparing food
  • Eating
  • Caring for a sick person
  1. Cover your mouth and nose with a clean tissue when you cough or sneeze. Throw the tissue away as soon as you use it. If you don't have a tissue, cover your nose and mouth with your upper sleeve or the crook of your elbow, not your hands.
  2. Keep your hands away from your mouth, nose and eyes. These are the places where germs can enter your body.
  3. Don't share eating utensils, drinking glasses or bottles with anyone else.
  4. Disinfect surfaces and objects that are commonly used, such as kitchen countertops, doors, sink handles and light switches. Harmful germs can live on surfaces for days, so it's important you clean them often with a disinfectant. Don't forget computer keyboards, phones and TV remotes.
  5. Avoid close contact with friends and family members. Keeping your distance from other people may reduce their risk of catching the flu from you.

Communicable Disease This information will help you learn about how communicable diseases make you sick and what you can do to prevent germs from getting into your body.

Contents

What are communicable diseases?
What do you "catch" when you get a communicable disease?
What are germs?
Try a germ quiz!!!
Are there different types of germs?
What are some examples of the different types of germs?
  • Bacteria
  • Viruses
  • Fungi
  • Protozoa
How do germs spread?
Can I protect myself from disease?


What are communicable diseases?
communicable disease such as a cold is a disease that spreads from person to person. Communicable diseases are diseases that you can "catch" from someone or something else. Some people may use the words contagious or infectious when talking about communicable diseases.

What do you "catch" when you get a communicable disease?
When a person becomes sick with a communicable disease it means a germ has invaded their body. Germs fear soap and water. Washing your hands well and often is the best way to beat these tiny warriors.
What are germs?
Germs are tiny organisms (living things) that may cause disease. Germs are so small and sneaky that they creep into our body without being noticed. In fact, germs are so tiny that you need to use a microscope to see them. We don't know what hit us until we have symptoms (runny nose, cough, sore throat, fever, etc.) that let us know we've been attacked!Germs are microbes. A microbe is a tiny living organism that can only be seen with a microscope. Microbes are the smallest form of life on Earth. Microbes have existed for millions, and possibly even billions of years. Although some microbes can make you sick or may even kill you. most are harmless, and some are extremely helpful. Microbes can be found virtually anywhere - in air, water, plants, animals and humans. A Germ is a microorganism that causes disease. Germs are also known as pathogens.

REMEMBER - ALL microbes are NOT Germs!

  • We could not digest our food without microbes.
  • Garbage would not decay without microbes.
  • Plants would not grow without microbes.
  • The gas we pass is caused by bacteria in our intestines.
  • Without microbes there would be no life on earth.
Are there different types of germs?
There are four major types of germs:
  • Bacteria
  • Viruses
  • Fungi
  • Protozoa
What are some examples of the different types of germs?
Let's talk about bacteria first.
Bacteria are EVERYWHERE! They live in sub freezing cold temperatures and boiling hot temperatures. They live up high in the sky and down deep below the ocean. In fact scientists have found colonies of bacteria thriving 1,600 feet below sea level without oxygen or sunlight. Scientists also think there are signs of microbial life on Mars! Some bacteria are harmful but most are harmless or even helpful.


Have you ever heard of people becoming sick after eating under cooked hamburger? The bacteria that can invade your body if hamburger is tainted with bacteria and not cooked thoroughly is E. Coli. E. Coli is a bacteria that can cause people to become very sick and possibly even kill them.
Another common bacteria associated with food poisoning is Salmonella. When this bacteria is eaten it causes nausea, vomiting, abdominal pain and diarrhea.
Did you ever become sick with Strep throat? Step throat is caused by a common type of bacteria called Streptococcus. Strains of streptococcus that cause throat and skin infections lurk worldwide and spread by touch or through the air. Strep is usually not fatal and can be treated with antibiotics.
If you live in the Chester County, PA area you probably know someone who has or had Lyme disease. This illness is caused by bacteria that spread through the bite of an infected deer tick.

Remember that ALL Bacteria are not bad. Some bacteria are good for our bodies, they help keep things in balance. Examples of bad things caused by bacteria are sore throats, ear infections, cavities, and pneumonia.

Enough with bacteria, what about viruses?
Viruses depend upon a host to survive, grow, and reproduce. A host is the plant or animal on which or in in which another organism lives. Viruses can't live outside of other living cells.
Viruses are the smallest and simplest microbes, just a ball of genes wrapped in a shell - about a millionth of an inch across. No one knows exactly how long they've been on Earth or how they evolved.
Once they are inside the body, viruses can spread and make people sick. They reproduce by injecting their genes into a cell to produce thousands of new viruses. Viruses cause chicken pox, measles, flu, and many other diseases.


Anyone, anywhere can get the flu, an extremely contagious viral disease. The influenza virus spreads through the air or by touch but usually is not fatal. There is no cure, but influenza often can be prevented with a yearly vaccination.
Chicken Pox is also caused by a virus.Most people who catch it are under 12 years of age. In olden times, the word "pox" meant curse. Wishing someone "a pox on your house" was wishing them bad luck. Although getting chicken pox seems like bad luck, "pox" now means skin eruptions or breakouts. And NO you didn't catch the virus from a chicken. Actually, chicken pox got its name from cicer, which is the Latin word for chick peas. People used to think that the bumps caused by the virus looked like chick peas on the skin!

Is there fungus among us?
Fungi are multi-celled plant-like organisms. Unlike other plants, fungi aren't able to produce their own food from soil, water, and air. Instead, fungi get their nutrition from plants, food, and animals.
Fungi thrive in warm, damp environments.
Most fungi are not dangerous.
An example of something caused by fungi is athlete's foot - that itchy rash that teens and adults sometimes get betweeen their toes.


What exactly is Athlete's Foot Fungus?
Athlete's foot is a very common skin condition. Many people will develop it at least once in their lives. It occurs mostly among teenage and adult males. It is uncommon in women and children under the age of 12.
You can prevent athlete's foot by following some simple rules:

  • Wash your feet daily.
  • Avoid tight footwear, especially in the summer.
  • Wear cotton socks. Don't wear socks made of synthetic materials.
  • If posible, go barefoot at home.
What are protozoa?
Protozoa are one-celled organisms like bacteria. Protozoa also love moisture and often spread diseases through contaminated water. Some protozoa cause intestinal infections.