Paper 1

• Specific heat capacity: amount of energy needed to raise the temperature of 1kg of a substance by 1 degree
• Power: rate at which energy is transferred or the rate at which work is done
• Power is measured in Watts
• Energy transfer of 1 joule per second is equal to a power of 1 watt
• Energy can be transferred, stored or dissipated but can not be created or destroyed
• What are the main energy sources available for use on Earth?

  fossil fuels(coal, oil, gas), wind, the tides, the sun, water waves, geothermal nuclear fuel, bio fuel
• Use of energy resources?

  Transport, electricity generation, heating
• Resistance of a thermistor decreases as the the temperature increases
• Direct potential difference: The potential difference between two points in a circuit.
• Alternating potential difference: The potential difference that changes direction at regular intervals.
• colour of: live wire

  brown
• Colour of: neutral wire

  Blue
• Colour of: earth wire


  green and yellow stripes
• Live wires: carry the alternating potential difference from the supply to the appliance
• Neutral wire: A wire that completes the circuit and has no current flowing through it
• Earth wire: safety wire to stop the appliance becoming live
• National grid: A system of cables and transformers that carries electricity around the country
• Electrical power is transferred from power stations to consumers using the national grid
• Particle model: The model that describes the structure of matter as a collection of tiny particles.
• Internal energy: total kinetic energy and potential energy of the particles in a system.
• Conduction: Heat transfer by vibration of particles (solids only).
• Thermal equilibrium: When two systems are at the same temperature, they have reached thermal equilibrium with one another.
• What is the energy called that is needed for a substance to change state

  Latent heat
• Specific latent heat of vaporisation: energy required to change a substance from liquid to vapour
• Atomic mass the bottom or top number on the fraction?

  Bottom

  
• Isotopes: atoms of the same element with different numbers of neutrons.

  
• Plum pudding model: there is a positive sphere with negative charge randomly placed within the sphere

  
• James Chadwick: Discovered the neutron
• Rutherfords atomic model: Protons and neutrons in the nucleus, electrons orbiting the nucleus

  
• Activity: rate at which a source of unstable nuclei decays
• Count-rate: number of decays recorded each second by a detector
• Alpha particle: consists of 2 neutrons and 2 protons
• Beta particle: A high-speed electron that is released from the nucleus as a neutron turns into a proton
• Gamma ray: A type of electromagnetic radiation with the longest wavelength and the highest frequency.
• Half-life: The time taken for the number of nuclei to halve.