Science Quiz - Atoms and Elements 02 (Answers)
This KS3 Science quiz will quiz you on atoms and elements. In 1661, Robert Boyle defined an element as a substance that could not be broken down into a simpler substance. At the start of the 20th century, scientists discovered that elements were made up from atoms which could be split into protons, neutrons and electrons. Now, we say that an element is a substance that contains only one type of atom. Each of the different atoms has a name and a chemical symbol. A chemical symbol always starts with a capital letter and is followed by either zero, one or two small letters e.g. I and Ir stand for iodine and iridium.
Chemical formulae are a quick way of writing down information about chemical substances - Cu is the shorthand for 'here we have one single atom of the element copper'.
The formula for water is H2O. Water is therefore not an element as it contains two different atoms - two atoms of hydrogen and one of oxygen. If there is no little number after a chemical symbol, it means there is only ONE atom. So in the formula H2SO4, there are 2 atoms of hydrogen (there is a small number 2 AFTER the symbol), only one atom of sulfur (there is NO small number after the symbol for sulfur) and 4 atoms of oxygen (can you see why?).
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You can find more about this topic by visiting BBC Bitesize - Atoms, elements and compounds
The idea of atoms has been around for thousands of years but it was only during the last two hundred years that scientists have found evidence they exist. In 1981, a very powerful microscope was developed that can be used to 'see' actual atoms
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The name of many elements ends in -ium
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There is no small number after the chemical symbol for sulfur therefore there is only one atom
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This is a simple representation of a molecule of the element hydrogen. You know that it is an element because there is only one type of atom in the formula
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A symbol MUST have ONE capital letter - no more, no less. That means the correct answer cannot be either options 2 or 3. Option 4 is tempting, but is the symbol for the metal iridium. But why use Fe for the symbol? The Latin word for iron is ferrum and quite a few symbols come from the Latin names for the elements. Iron is very common, so, if you didn't already know it, it should not be too long before you have to remember that Fe is the chemical symbol for iron
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About three-quarters of all elements are metals
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It is a toxic (poisonous) metal
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If you did not know the answer, you could easily have looked up the chemical symbols to find out what elements they represent
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Counting the capital letters in the formula immediately tells you that answers 2 and 3 must be incorrect (there are 3 capitals so there must be three elements). It is then simply a case of looking up the symbols on the periodic table or in a list of elements
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Copper, aluminium and zinc are not attracted by magnets
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