Element, Compound and Mixture

Hello readers! Today’s topic will be on “Elements, Compounds and Mixtures” as requested by another Science teacher, Mrs Fromey. Bonjour Madame Fromey! Thanks for visiting my blog ;) I hope you’ll be reading this post and hopefully it’ll help your lessons :)

Elements

An element is a pure substance which contain only one kind of atom. Element cannot be broken down into two or more simpler substances by either physical or chemical means. It can exists as either atoms (e.g. Argon, Copper, Gold) or molecules (e.g. Hydrogen, Bromine, Oxygen)

You might now wonder...what are atoms and molecules? Atom is the smallest particle of an element whereby molecule is made up of two or more atoms that are chemically combined together.

Still confuse? Let me give you several diagrams that might help you understand more about elements that can exist as either atoms or molecules.

Examples of atoms:

Noble gas atoms such as Helium, Neon and Argon

Gold atoms

Examples of molecules:

Molecules of bromine gas (on top) and liquid bromine (below)

Molecules of elements

Below is tabular display of chemical elements called the Periodic Table of the Elements which are organized based on its properties. (please click picture below to enlarge)

 Compounds

A compound is a pure substance which is made of two or more elements chemically combined together. It can be broken down into two or more simpler elements by chemical means only (but not by physical means). It has different properties from its component elements and it always contain the same ratio of its component atoms (fixed composition).

Examples of compounds: 

As you can see from the above examples, the compound is made up of different elements (two or more) chemically combined together.


Making a compound from its elements

Example: Making water from hydrogen and oxygen (2H2 + O2 --> 2H2O)

  

Notice that both elements are in gaseous state initially but once they form compound water, it is liquid. This shows that a compound has different properties from its component elements.

Another example is brown copper burns with green chlorine gas and form yellowish-green copper chloride.

Breaking a compound into its elements

Example: Breaking down molten sodium chloride into sodium and chlorine by electrolysis 

(2NaCl --> 2Na + Cl2)

**Electrolysis is the process of breaking down compounds by using an electric current

 Mixtures

A mixture is made of two or more substances mixed but not chemically joined together. It can be separated into its components by physical means. It has the same properties as all its component substances and do not have a fixed composition of the substances.

An example of mixture is air which consists of different gases such as nitrogen, oxygen, carbon dioxide and water vapour. All of these gases are colourless and odourless and so does air. Air still retains many of the properties of its components.

Other examples of mixtures are muddy water which can be separated into soil and water by filtration or a mixture of copper powder with iron filings which can be separated by using a magnet.

Below are diagrams of several other examples of mixtures to help you understand better:

A mixture of two elements (e.g. argon gas and hydrogen gas)

A mixture of an element and a compound (e.g. hydrogen and ammonia gas)

A mixture of two compounds (e.g. carbon dioxide and water vapour)

Click the link below to test your knowledge on Elements, Compounds and Mixtures. Good luck and have fun playing the quiz :)

http://www.funtrivia.com/playquiz/quiz148865110c980.html

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"What's the Matter??"

What is matter? Matter is anything that has mass and occupies space (volume). Matter is everything around you. So rocks, water, air, plants and animals are matter because they all have mass and occupy space. We can classify matter into 3 states of matter i.e. solid, liquid and gas. 

Solid

Solids can be hard or soft, heavy or light but all solids  have definite mass, definite shape, definite volume and do not flow.

Examples of solids are apples, books, chairs, soil and flowers.

Liquid

Some liquids are coloured while others are not. However, all solids  have definite mass, indefinite shape(it takes the shape of the container), definite volume and can flow.

Examples of liquids are water, oil, alcohol and bromine water.

Gas

Some gases have smell while others are odourless, some are coloured while other gases are colorless but all gases  have definite mass, indefinite shape, indefinite volume and can flow.

Examples of gases are air, nitrogen dioxide, ammonia and hydrogen.


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What is matter made up of? Scientists think that matter is made of tiny particles. Kinetic particle theory states that all matter is made up of particles which are constantly moving in all directions.

 >> click to enlarge << 

                            

                                     

Solid                                      Liquid                                        Gas   

Here's a song video that might help you remember what we learn today :) I know this ain't Justin Bieber/Taylor Swift/K-Pop's song but it is a catchy song, right? Sing along then and you might as well learn the lyrics to this States of Matter song. ;)

p/s: please turn off the sound/music from the game below before you play the video. Thanks and enjoy!

                                 "Gas~~Liquid~~Solid~~
                                  The states of matter...
                               I've got gas~liquid~solid~
                               I've got gas~liquid~solid~

                               Gas has a definite mass,
                                        indefinite shape
                             and indefinite volume too.
                        On heating it expands real large
                           and it's easily compressible.  (2x)

                            Liquid has a definite mass,
                                      indefinite shape
                             and definite volume too.
                        On heating it expands slightly
                        and has a low compressibility. (2x)

                             Solid has a definite mass,
                                      a definite shape
                             and definite volume too.
                       On heating it expands real low
                       and has no compressibility." (2x)

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Congratulations!

Congratulations to the 'Top 3 Scorers' in Science (End of Year Exams 2011). I wish I could give presents to all students who scored 90+ in my subject but . . . . . I have a limited budget xp Maybe next time?? if you could get an A for me on your SPE... I know you can do it :)

Let me share an inspirational quote to all my readers here:

"The difference between a successful person and others is not a lack of strength and a lack of knowledge, but rather lack of will." - Vince Lombardi

Yeah look how true it is. If you want to achieve your goals, you must have the will and the burning desire to do whatever it takes to accomplish it. 

So what are you waiting for now? Get up and do something about it! ;)

 Photos of the gifts I gave to the 'Top 3 Scorers' in Science this afternoon. 

I hope they all like my "Sciencey" gifts I got for them ;)

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Celebrating 1000 blog hits! B)

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Birthday Shoutout!!!

Have you seen today's Google doodle? It is made to a German physicist, Heinrich Rudolf Hertz who was born on February 22, 1857. So HAPPY 155TH BIRTHDAY, HERTZ!

For those who have never heard of Hertz before, here's a biography on him taken from http://www.ideafinder.com/history/inventors/hertz.htm

"Heinrich Rudolf Hertz, German physicist, born in Hamburg, and educated at the University of Berlin.  From 1885 to 1889 he was a professor of physics at the technical school in Karlsruhe and after 1889 a professor of physics at the University in Bonn.  Hertz clarified and expanded the electromagnetic theory of light that had been put forth by the British physicist James Clerk Maxwell in 1884.  Hertz proved that electricity can be transmitted in electromagnetic waves, which travel at the speed of light and which possess many other properties of light.  His experiments with these electromagnetic waves led to the development of the wireless telegraph and the radio. 

His name also became the term used for radio and electrical frequencies: hertz (Hz), as in kilohertz (kHz) or megahertz (MHz). The hertz designation has been an official part of the international metric system since 1933. Before Hertz gained professorships in Karlsruhe and Bonn, he had studied under the famous scientist Hermann von Helmholtz in Bonn, and it was Helmholtz who encouraged Hertz to attempt to win the science prize that led to some of Hertz's most important discoveries. From 1885 to 1889 Hertz became the first person to broadcast and receive radio waves, and to establish the fact that light was a form of electromagnetic radiation. (The Italian Marconi didn't begin his own wireless experiments until 1894, based on the earlier work of Hertz, Maxwell, and others.) Hertz probably would have gone on to make many more scientific contributions, but he died quite young, less than a month before his 37th birthday." 

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Photo of the Day!

Hi there! I decided to post something different today. A photo to share with you in regards to the previous post.

I asked my students to revise their notes on "Food and Its Importance" this morning as they will be having their assessment this coming Thursday. As I go around the class, these drawings made by one of the boys caught my attention. LOL! I find it amusing but somehow, I like it cause I do find it helpful for him to remember. I must say this is creatively smart of him to do this during my lesson. I must give him credit for that :)  BUT PLEASE DON'T TAKE THIS THE WRONG WAY STUDENTS! I don't want you to scribble something irrelevant to the topic I teach you at class! As I've suggested you during class, I want you start learning to take useful notes during my lesson in addition to the handouts I gave you cause it'll help you learn better.

So anyways, here's the photo that I took from this morning (with his permission)...

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"Yummy , yummy, yummy, I got love in my tummy~"

*stomach growl* Are you hungry? Wanna go grab something to eat now? Wait...what's your diet like? Are you eating the right foods? Today’s lesson is on “Food and Its Importance” as requested by one of my student. I hope he’ll be reading this post :) Alright, let’s just get right to it.

So the amount and type of food that we eat on a daily basis is very important to both health and performance. Food provides us the energy we need to do work, for growth, to build and repair damaged tissues, to keep us warm and helps our bodies to stay healthy. Not getting enough nutrients can lead to a variety of illnesses which shall be discussed later on.

The process of taking food into the body and using it for the living parts of the body is known as nutrition. There are 7 classes of food i.e. 

1) Carbohydrates     2) Proteins     3) Fats     4)Fibre (Roughage)    

5)Vitamins   6)Minerals    7)Water

1

 All of the above food groups with the exception of water are nutrients.

1)  Carbohydrates

Carbohydrates are the body’s main source of energy. We need energy for growth, movement and to keep us warm.

Carbohydrates can be classified into two types i.e. (i) Sugar (simple carbohydrate) and (ii) Starch (complex carbohydrate).

Simple carbohydrates or simple sugars can be found in foods such as fruits, chocolates, cakes, fizzy drinks and milks. They can provide a lot of energy for immediate use, but does not contain other useful nutrients like in a lollipop.

Complex carbohydrates or starches include rice, bread, potatoes, biscuits, pasta and cereals are good sources of energy. The body can easily store energy from carbohydrates for rapid use by the muscles. Starchy foods often also contain lots of useful vitamins, minerals and fibre.

However, eating too much carbohydrate can cause the excess glucose turns into fatty acids and be stored as body fat.

2)   Proteins

Proteins are needed for growth and the repair of body tissues. They are also needed for the formation of enzymes, hormones, haemoglobin and antibodies.

Examples of foods rich in proteins are egg white, meat, fish, nuts and beans.

Lack of proteins in your diet can cause kwashiorkor. The physical examination may show an enlarged liver and abdomen. To prevent kwashiorkor, make sure your  diet has enough carbohydrates, fat and protein.

3)   Fats

Fats are also used for energy, but only when stores of carbohydrate run low. Fat contains more than twice as much energy as carbohydrates. 

Fats are usually solids (e.g. butter, margarine and cheese). When the fat is liquid at room temperature, it is called oil. (e.g. cooking oil) 

Eating too much fat may lead to obesity, which is unhealthy.

4)   Fibre (roughage)

Fibre is also known as roughage which is made up of cellulose from plant cell walls. Fibre cannot be digested in our body. It holds a lot of water so that our faeces remains soft and can pass from our body easily. 

Fibre helps to prevent constipation which is a difficulty in passing out faeces from our body as a result of lack in fibre which causes the faeces to become hard and dry.

Examples of dietary fibre are whole wheat and grain products, fruits and vegetables.

5)   Vitamins

Vitamins are organic compounds needed in small amounts by our body for health and growth. A deficiency (lack) of vitamins will lead to certain diseases.

6)   Minerals

Minerals are inorganic substances needed in small amounts by our body in order to stay healthy.

7)   Water

Water makes up 70% of our body. It is the main components of our blood and body fluids. It is vitally important that you drink enough water.

Water carries substances around the body and helps to remove wastes. It is the medium for chemical reactions within the body.

Fluids include fresh water and all other liquids like fruit juice, soft drinks, coffee, tea, milk and soup. 

Milk is a mixture of nutrients with water. A mother’s milk is the most suitable food for the new born babies. Mother’s milk contains all the necessary nutrients to feed the baby properly and it is rich in antibodies, which protect the baby against diseases.

 Balanced diet

 

Everyone should try to eat a healthy, balanced diet. A balanced diet must contain all the 7 classes of foods (carbohydrate, protein, fat, fibre, vitamins, minerals and water) in the correct proportions. Each nutrient is needed for the proper functioning of the human body. The effects of not having a balanced diet can prove to be harmful to the body.

 

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