Please follow these instructions to ensure correct and speedy answering of questions
 
  You can answer the Questions in any order.
Marks for each Question reflect it's difficulty and indicates in minutes how long should be spent answering it.
Answer each Question carefully, as submitting a wrong multi-choice answer will mark the whole Question as wrong.
Many Questions have more than one right answer so selecting all of these gets you the maximum score.
How to type an answer
  1. Use the star symbol * for the multiplication symbol not the letter x
  2. Use the / key (same key as the ? key) for the division symbol
  3. Write powers as x2 (for x squared) or x/y2 (for x divided by y squared)
  4. Leave a single space between mathematical symbols except division, so x2 - 2y3 (not x2-2y3)
  5. Use the / division symbol for fractions, so 1/5 is one fifth
  6. Include the units of measurement as used in each Question, when requested
  7. Write complete sentences when answering the extended text questions for maximum marks
  8. You should not add punctuation to your answers but DO start each 'sentence' on a new line
After attempting each Question,  Press it's mark button
    Your answer(s) to just that Question will then be marked.
If not fully correct, please try again by pressing the reset button
   You may use these two buttons as many times as you wish
If you need help there is a hint button to provide a clue shown after two incorrect attempts,
    but halves this question's remaining marks if used.
Each question must be attempted 3 times before a reveal button is available to show answers
    but freezes this question's marks if used.
If  unattempted questions remain on pressing this button, you will be prompted to answer them.
If you wish to leave the Exercise then press this button and all your answers will be marked.
If you need to save your score, you can do so as a plain text file or as a spreadsheet
   follow the on-screen instruction to do this.
When you have scored an Exercise and you wish to leave press this button which will return you to the Chemistry Homepage
   
You can quit an Exercise at any time by using this button. No score will be calculated.