Ad Astra 2016
Year 11
Physics &
Chemistry
1 Notemaking in Physics
2 Notemaking in Chemistry
Conductivity of heat and electricity
Metals are good conductors of electricity because of the mobility of the delocalised
electrons within the lattice of positive ions. When a metal is used in an electrical
circuit, electrons entering one end of the metal cause a similar number of electrons
to be displaced from the other end, and the metal conducts. In the solid state,
the positive ions do not act as charge carriers. They remain vibrating about fixed
positions within the lattice, as the delocalised electrons move. However, when a
molten metal conducts electricity, both the delocalised
electrons and the positive ions are able to move and act as charge carriers.
The delocalised electrons are also responsible for the rapid transmission of heat
energy in metals. When one end of a piece of metal is heated, the kinetic energy
of the positive ions and the delocalised electrons in the heated region increases,
that is, their rate of movement increases. The heat energy is conducted along the
piece of metal by the more energetic electrons and positive ions colliding with less
energetic electrons and ions. However, because the electrons are delocalised, they
are able to move quite freely through the lattice and so cause a transfer of the
heat energy along the metal that is more rapid than for most other materials.
Malleability and Ductility
The delocalised electrons in metals do not ‘belong’ to any particular positive
ion in the lattice, so metallic bonding is said to be non-directional. Therefore, if
sufficient force is applied to the metal, one layer of positive ions can slide, or slip,
over another without disrupting the metallic bonding. This means that, after
the layer of positive ions has moved, there are still attractive forces between
the delocalised electrons and the positive ions holding the lattice together in the
newly deformed metal. As a result, metals can be hammered readily into sheets
or drawn into wires without breaking,
Draw a table in the space below to summarise the properties of metals discussed above 3 Physics Scenario
A group of students are using a pendulum in a Physics experiment. The
motion of the pendulum bob is shown in the diagram below.
The students get ready to start the experiment. They raise the pendulum bob,
which has a mass of 0.2 kg through a vertical height of 0.1 m and allow it to
swing freely.
(a)
Calculate the gravitational potential energy of the pendulum bob before
they release it?
(3 marks)
(b)
What is the velocity of the pendulum bob at its fastest point?
(4 marks)
(c)
Will the pendulum return to the same height it was released from?
(1 mark)
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4 (d)
Explain your reasoning in (c).
(3 marks)
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Chemistry Scenario
The labels fell off four test bottles containing solutions of sodium carbonate, sodium nitrate, sodium sulfate and sodium bromide. You have been asked to precipitation reactions to identify them. The student was provided with labelled solutions of lead (II) nitrate and magnesium nitrate and barium nitrate and told to use these to correctly identify which solutions were in the four test tubes. The results are summarised in the table below. Use your knowledge of solubility rules to identify which of the sodium salts were in each of the four test tubes. Test Tube 1 Test Tube 2 Test Tube 3 Test Tube 4 Addition of 10 White
White White precipitate
drops of No Reaction precipitate precipitate Pb(NO3)2(aq) Addition of 10 White drops of No Reaction No Reaction No Reaction precipitate Mg(NO3)2(aq) Addition of 10 White White drops of No Reaction No Reaction precipitate precipitate Ba(NO3)2(aq) Test Tube 1 contains Test Tube 2 contains Test Tube 3 contains Test Tube 4 contains 5 Chemistry Data Sheet Questions Q1: What is the atomic number of Cobalt? Q2: What is the colour of silver oxide? Q3: What is the colour of Iodine in an organic solvent? Q4: Strontium belongs to which period and group? Q5: Is silver sulfate soluble or insoluble? Q6: What is the value of the Universal Gas Constant, R? Q7: What is the colour of the element Bromine? Q8: Which solutions would be coloured pink? Q9: 1 atm is equivalent to how many kPa? Q10: What is the valence shell electron configuration of Se in its ground state? Physics Data Sheet Questions Q1: What factor does the metric prefix ‘pico’ represent? Q2: What is the approximate quality factor for slow neutrons? Q3: What is the formula for change in momentum (impulse)? Q4: What is a tonne equivalent to in kilograms? Q5: What is the mass-­‐energy relationship? Q6: What is the rest mass of an electron? Q7: What is the atomic number of Uranium? Q8: What is the latent heat of fusion for H2O? Q9: What is the mass-­‐energy equivalent? Q10: What is the symbol for the metric prefix ‘micro’ 6