topic 5: Materials
In this unit we will be looking at atoms, elements and compounds. All matter is made from atoms. Atoms are very, very small. A molecule is formed when atoms join together by chemical bonds. There are many different elements, which are made up of atoms. Elements can be divided into metals and non-metals. Chemical symbols and formula are used to represent elements and compounds. There are over a hundred different types of atom, called elements. The atoms of a particular element are identical to each other. They cannot be changed chemically into any different element.
Define matter as anything that has both mass and volume.
Matter is all the “stuff” that exists in the universe. Everything you can see and touch is made of matter, including you! The only things that aren’t matter are forms of energy, such as light and sound. In science, matter is defined as anything that has mass and volume. Mass and volume measure different aspects of matter.
- Mass is a measure of the amount of matter in a substance or an object.
- Volume is a measure of the amount of space that a substance or an object takes up.
Outline the basic structure of an atom (simple Bohr model to include protons, electrons, neutrons)
Atoms are the basic units of matter and the defining structure of elements. Atoms are made up of three particles: protons, neutrons and electrons.
Protons and neutrons are heavier than electrons and reside in the center of the atom, which is called the nucleus. Electrons are extremely lightweight and exist in a cloud orbiting the nucleus.
Protons and neutrons are heavier than electrons and reside in the center of the atom, which is called the nucleus. Electrons are extremely lightweight and exist in a cloud orbiting the nucleus.
Identify the terms atomic number and atomic mass
The atomic number of an atom is the number of protons it contains. All the atoms of a particular element have the same atomic number (number of protons). The atoms of different elements have different numbers of protons. For example, all oxygen atoms have 8 protons and all sodium atoms have 11 protons.
The mass number of an atom is the total number of protons and neutrons it contains. The mass number of an atom is never smaller than the atomic number. It can be the same, but is usually bigger.
The mass number of an atom is the total number of protons and neutrons it contains. The mass number of an atom is never smaller than the atomic number. It can be the same, but is usually bigger.
Identify how elements are arranged in patterns in the Periodic Table
Elements are arranged in the Periodic Table in order of increasing atomic number. The Periodic Table allows chemists to make accurate predictions of physical properties and chemical behaviour for any element based on its position. Features of the table are; Groups- vertical columns within the table which will contain elements with similar chemical properties resulting from a common number of electrons in the outer shell, Periods- rows of elements arranged with increasing atomic number demonstrating an increasing number of outer electrons and a move from metallic to non-metallic characteristics. Key groups of elements which can be recognised are metals and non-metals, alkali metals, halogens, noble gases and transition elements. The gaseous elements are generally to be found clustered in the top right corner of the table.
Utilize the periodic table as tool to identify the atomic number and atomic mass of an element
The periodic table of the elements contains a wide variety of information such as element symbols, atomic number and atomic mass is most common, but the periodic table can contain even more data than previously expected. This will show you how to use a periodic table to gather information about the elements.
The periodic table contains informative cells for each element arranged by increasing atomic number and chemical properties.
The periodic table contains informative cells for each element arranged by increasing atomic number and chemical properties.
Describe the properties of metals and non-metals
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Metals:
Strong Malleable and ductile React with oxygen to form basic oxides Sonorous High melting and boiling points Good conductors of electricity Good conductors of heat Mainly solids at room temp. Shiny when polished When they form ions, the ions are positive High density |
Non Metals:
Brittle Brittle React with oxygen to form acidic oxides Dull sound when hit with hammer Low melting and boiling points Poor conductors of electricity Poor conductors of heat Exception mercury - liquid at room temp. Solids, liquids and gases at room.temp. Dull looking When they form ions, the ions are negative - except hydrogen that forms a positive ion, H+. Low density |
Common Metals and Non-Metals
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Metals:
Calcium Potassium Lead Copper Aluminium Zinc Lithium |
Non-metals:
Sulphur Oxygen Chlorine Hydrogen Bromine Nitrogen Helium |
The uses of metals are related to their properties:
The uses of non metals are related to their properties:
- They are made into jewellery due to their hard and shiny appearance.
- They are used to make pans, since they are good conductors of heat.
- They are used in electrical cables, because they are malleable, ductile and good conductors of electricity.
- They are strong so used to build scaffolding and bridges.
- They make a ringing sound, sonorous, hence their use in bell making.
The uses of non metals are related to their properties:
- Used as insulating material around wire cables since they do not conduct electricity.
- Used to make pan handles as they are poor conductors of heat.
Distinguish between:
- Single atoms
- Molecules composed of atoms from one element (H2 /O2/S8)
- Molecules composed of atoms of different elements in compounds (CO2/H2O/CH4/O2)
Chemists like to classify things. One way that chemists classify matter is by its composition. All matter can be classified as mixtures, elements and compounds. All matter is composed of atoms and groups of atoms bonded together, called molecules. Substances that are made from more than one type of atom bonded together are called compounds. Compounds and elements that are combined physically, but not chemically, are called mixtures.
Mixtures
Mixtures
- Two or more substances that are not chemically combined with each other- they are mixed together.
- Mixtures can be separated by physical means.
- The “things” in a mixture keep their individual properties.
- Simplest form of pure substance.
- They cannot be broken down into anything else by physical or chemical means.
- Pure substances that are composed of two or more elements chemically bonded together.
- Compounds can be broken into simpler substances by chemical mean
Use symbols in equations
image from bbcbitsize.com
Use of chemical symbols represent the elements. For example, C stands for carbon, O stands for oxygen, S stands for sulphur and Na stands for sodium. For a molecule use the chemical symbols of the atoms it contains to write down its formula.
The formula for carbon monoxide is CO. It tells you that each molecule of carbon monoxide consists of one carbon atom joined to one oxygen atom. Take care when writing your symbols and formulae. Be careful about when to use capital letters. For example CO means a molecule of carbon monoxide but Co is the symbol for cobalt.
If the molecule contains more than one atom of an element we use numbers to show this. The numbers are written below the element symbol. For example, the formula for carbon dioxide is CO2 . It tells you that each molecule has one carbon atom and two oxygen atoms.
Take care when writing these formulae. The small number go at the bottom. For example CO2 is correct but CO2 is wrong.
Some formulae are more complicated. For example, the formula for sodium sulphate is Na2SO4 . It tells you that sodium sulphate contains two sodium atoms (Na2 ), one sulphur atom (S) and four oxygen atoms (O4 )
The formula for carbon monoxide is CO. It tells you that each molecule of carbon monoxide consists of one carbon atom joined to one oxygen atom. Take care when writing your symbols and formulae. Be careful about when to use capital letters. For example CO means a molecule of carbon monoxide but Co is the symbol for cobalt.
If the molecule contains more than one atom of an element we use numbers to show this. The numbers are written below the element symbol. For example, the formula for carbon dioxide is CO2 . It tells you that each molecule has one carbon atom and two oxygen atoms.
Take care when writing these formulae. The small number go at the bottom. For example CO2 is correct but CO2 is wrong.
Some formulae are more complicated. For example, the formula for sodium sulphate is Na2SO4 . It tells you that sodium sulphate contains two sodium atoms (Na2 ), one sulphur atom (S) and four oxygen atoms (O4 )
Write word equations
A word equation describes a chemical change using the names of the reactants and products. To write a word equation, write the names of the reactants to the left of the arrow separated by a plus sign; write the names of the products to the right of the arrow, also separated by plus signs
NEVER USE AN EQUAL (=) SIGN
NEVER USE AN EQUAL (=) SIGN
Explain how recycling can save resources and energy
Recycling means to use something again. Newspapers can be used to make new newspapers. Aluminum cans can be used to make new aluminum cans. Glass jars can be used to make new glass jars. Recycling often saves energy and natural resources through conservation.
It almost always takes less energy to make a product from recycled materials than it does to make it from new materials. Using recycled aluminum scrap to make new aluminum cans, for example, uses 95 percent less energy than making aluminum cans from bauxite ore, the raw material used to make aluminum.
Natural resources are riches provided courtesy of nature. Natural resources include land, plants, minerals, and water. By using materials more than once, we conserve natural resources. In the case of paper, recycling saves trees and water. Making a ton of paper from recycled stock saves up to 17 trees and uses 50 percent less water.
It almost always takes less energy to make a product from recycled materials than it does to make it from new materials. Using recycled aluminum scrap to make new aluminum cans, for example, uses 95 percent less energy than making aluminum cans from bauxite ore, the raw material used to make aluminum.
Natural resources are riches provided courtesy of nature. Natural resources include land, plants, minerals, and water. By using materials more than once, we conserve natural resources. In the case of paper, recycling saves trees and water. Making a ton of paper from recycled stock saves up to 17 trees and uses 50 percent less water.
Key Terms
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elements
electron shell nobel gas ferrous group compound bond mass re-use sustainable |
atoms
chemical symbol alkali metal molecule period chemical reaction mineral conduct recycle |
protons
metals mallleable mixture metalloid physical reaction oxide insulator renewable |
electrons
non metals brittle compound homogeneous solute reactants matter pollution |
neutrons
halogen ductile atomic number heterogeneous solvent substrate reactivity plastics |
Class Assignments
Atoms Family (pdf)
Adapot An Element (pdf)
Atomic Math Challenge (pdf)
Chemistry Scavenger Hunt
Meeting The elements Song worksheet
Atoms and Elements Revision Poster
Counting Atoms
Periodic Table Basics
Periodic Table Revision map
Messing With Mixtures practical
Useful Links
Matter from Chem4Kids
Atoms from Chem4Kids
Periodic Table and Elements from Chem4Kids
Name That Atom
Check out this video clip on "Atoms".
Science Spot
BBC Bitesize Atoms, Elements and Compounds
BBC Bitesize Atoms and Elements Activity
Royal Society of Chemistry Interative Periodic Table
Royal Society of Chemistry Periodic Table Podcast
Comic Book Periodic Table
Atoms Family (pdf)
Adapot An Element (pdf)
Atomic Math Challenge (pdf)
Chemistry Scavenger Hunt
Meeting The elements Song worksheet
Atoms and Elements Revision Poster
Counting Atoms
Periodic Table Basics
Periodic Table Revision map
Messing With Mixtures practical
Useful Links
Matter from Chem4Kids
Atoms from Chem4Kids
Periodic Table and Elements from Chem4Kids
Name That Atom
Check out this video clip on "Atoms".
Science Spot
BBC Bitesize Atoms, Elements and Compounds
BBC Bitesize Atoms and Elements Activity
Royal Society of Chemistry Interative Periodic Table
Royal Society of Chemistry Periodic Table Podcast
Comic Book Periodic Table
Video Clips
Have fun with Bill Nye as he talks about atoms and elements
Science expert Emerald Robinson explains what an atom is.
Scientists at the University of California Los Angeles have found a way to create stunningly detailed 3D reconstructing of platinum nanoparticles at an atomic scale. These are being used to study tiny structural irregularities called dislocations.
Just how small are atoms? And what's inside them? The answers turn out to be astounding, even for those who think they know. This fast-paced animation uses spectacular metaphors (imagine a blueberry the size of a football stadium!) to give a visceral sense of the building blocks that make our world.
Hank gives us a tour of the most important table ever, including the life story of the obsessive man who championed it, Dmitri Mendeleev. The periodic table of elements is a concise, information-dense catalog of all of the different sorts of atoms in the universe, and it has a wealth of information to tell us if we can learn to read it.
The elements had been listed and carefully arranged before Dmitri Mendeleev. They had even been organized by similar properties before. So why is Mendeelev's periodic table the one that has endured? Lou Serico explains via Ekaaluminium, an element whose existence Mendeelev predicted decades before it was discovered.
A fun way to learn the elements of the periodic table
BBC Bitesize KS3 Revision Metals and Nonmetals
BBC Bitesize KS3 Revision Elements, Compounds and Mixtures
This documentary is about the importance of recycling and changing our habits to preserve our planet.
