1.1 Elements and Compounds

• Atoms, elements, molecules and compounds
• Symbols of common elements (oxygen, carbon, hydrogen, nitrogen, iron, aluminium, copper, silver, gold, chlorine, sodium, mercury, lead)
• Word equations for reactions of elements to form compounds (sodium chloride, water, carbon dioxide, copper oxide, aluminium oxide)
• Uses of some common elements in society (jewellery, construction, electricity, food nutrients, mineral elements, medals)

• explain the relationship between an atom, an element, a molecule and a compound
• assign symbols to selected elements
• write word equations to represent reactions of selected elements to form compounds
• outline the applications of common elements in the society
• appreciate the information on packaging labels of commonly consumed substances

“Why is it important to use symbols for representing elements in day-to-day life?”

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1. What an atom is
   40 min · 1 practice tasks · quiz
   The smallest particle of an element, its parts, and just how small it really is.
2. What an element is
   40 min · 1 practice tasks · quiz
   A substance made of only one kind of atom, and how many of them there are.
3. What a molecule is
   40 min · 1 practice tasks · quiz
   Two or more atoms joined together, whether they are the same kind or different kinds.
4. What a compound is
   40 min · 1 practice tasks · quiz
   Different elements chemically joined, and why the result behaves nothing like what went in.
5. How they all fit together
   40 min · 1 practice tasks · quiz
   Putting atom, element, molecule and compound in order and telling them apart reliably.
6. Why elements have symbols
   40 min · 1 practice tasks · quiz
   What a symbol is, the rule for writing one, and why every country uses the same set.
7. Symbols from the English name
   40 min · 1 practice tasks · quiz
   Six element symbols taken straight from the name, and why some need a second letter.
8. Symbols of the metals
   40 min · 1 practice tasks · quiz
   Seven common metals, their symbols, their uses, and the two that are poisonous.
9. Symbols that come from Latin
   40 min · 1 practice tasks · quiz
   Why Fe means iron and Pb means lead: the old names behind seven awkward symbols.
10. What a word equation shows
    40 min · 1 practice tasks · quiz
    Reactants, the arrow and products, and the rules for writing an equation correctly.
11. Making sodium chloride
    40 min · 1 practice tasks · quiz
    The first word equation in full, and the naming rule that gives the -ide ending.
12. Making water and carbon dioxide
    40 min · 1 practice tasks · quiz
    Two compounds made from non-metals, why water keeps its old name, and the danger of carbon monoxide.
13. Making copper oxide and aluminium oxide
    40 min · 1 practice tasks · quiz
    Two metals meeting oxygen, and why one layer protects the metal while another does not.
14. Finding the elements in a compound
    40 min · 1 practice tasks · quiz
    Reading the name of a two-element compound backwards to work out what is inside it.
15. Elements in jewellery and medals
    40 min · 1 practice tasks · quiz
    Why gold and silver are chosen for things meant to last, and what makes them valuable.
16. Elements in construction and electricity
    40 min · 1 practice tasks · quiz
    Iron, aluminium and copper, and the property that decides where each one is used.
17. Elements the body needs
    40 min · 1 practice tasks · quiz
    Mineral elements needed in tiny amounts, what each does, and what happens without them.
18. Reading a packaging label
    40 min · 1 practice tasks · quiz
    Finding the elements and compounds on a real label, and using it to compare products.