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The following slides should help you with your revision, but should not be your only form of revision. Remember to use your notes, a textbook, websites and Past Papers to help you. You can also ask a chemistry teacher for help too.
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The following slides should help you with your revision, but should not be your only form of revision. Remember to use your notes, a textbook, websites and Past Papers to help you. You can also ask a chemistry teacher for help too.
Write the number of protons, neutrons and electrons in Na with a mass no of 23 Protons – 11 Neutrons – 12 Electrons - 11
What is the mass number? The number of protons plus the number of neutrons in the nucleus of the atom.
What is an ion? An atom which has either gained or lost an electron
What is an isotope? Atoms with the same atomic number but different mass number
Why are noble gases un-reactive? They have a stable electron arrangement.
How can atoms achieve a full outer electron shell? Electrons by losing, gaining or sharing outer shell electrons.
What is a covalent bond? The attraction of each positive nucleus for the shared pair of electrons.
What are the 7 diatomic elements? Hydrogen Nitrogen Oxygen Fluorine Chlorine Bromine Iodine
Why do covalent molecules have low melting and boiling points? Due to weak forces of attraction between the molecules.
What is an ionic bond? The electrostatic forces of attraction between positive and negatively charged ions.
How many protons does39 K+ have? No. of protons = 19.
How many neutrons does39 K+ have? No. of neutrons = 20.
How many electrons does39 K+ have? No. of electron = 18.
What’s the electron arrangement for39 K+ ? Electron arrangement 2,8,8.
Which atom has the same electron arrangement as39 K+ ? Argon.
How many protons does31 P3- have? No. of protons = 15.
How many neutrons does31 P3- have? No. of neutrons = 16.
How many electrons does31 P3- have? No. of electron = 18.
What’s the electron arrangement for31 P3- ? Electron arrangement 2,8,8.
Which atom has the same electron arrangement as31 P3- ? Argon.
You need to revise writing formulae for ionic compounds. Look in your notes for help and practise writing formulae. Including Ionic formulae!!
You need to revise calculating formula mass, mass, no of moles etc Look in your notes for help and practise calculating no of moles and concentration