Science yr 8

• Series


  One route, flow through all components, connected end to end
• Parallel


  1+ route, does not flow through all components, connected side by side
• When bulbs are added in a series


  The bulbs get dimmer
• When bulbs are added in parallel


  The bulbs stay at the same brightness
• If 1 bulb is unscrewed, the rest stay on
• Atom


  Smallest particle of an element that still retains its properties
• Subtomic particles


  • Proton
  • Neutron
  • Electron
• Shells


  Electron shells around the nucleus
• Group


  Vertical column of elements with similar properties
• Period


  Horizontal row of elements
• Metals lose electrons (gain positive charge)
• Non-metals gain electrons (gain negative charge)
• Ionic bonding


  Formed by combining metals and non-metals, transfer of electrons
• Covalent bonding


  Formed between non-metals, sharing of electrons
• Metallic bonding

  Force of attraction between metal ions and delocalised electrons

  
• Conductor


  Conducts electricity, allows electric current to flow

  
• Insulator

  Does not conduct electricity, prevents flow of electric current
• Resistor


  Limits and regulates the flow of electric current
• Electric resistance value can be tested
• Variable resistor


  Resistor with adjustable resistance
• Series circuit


  One route, flow through all components
• Parallel circuit


  1+ route, does not flow through all components
• In a series circuit, when one bulb is unscrewed the rest stay on
• In a parallel circuit, when one bulb is unscrewed the rest stay at the same brightness
• Ampere


  Unit for electric current
• Voltage


  Measure of potential difference
• Resistance


  Measure of opposition to electric current flow
• Power


  Rate of energy transfer
• Speed = distance / time
• Acceleration = change in speed / time
• Momentum = mass x velocity
• Pressure = force / area
• Dominant allele
• Recessive allele
• Genetic disorders


  • Albinism
  • Cystic fibrosis
• Biodiversity

  Measure of variety of life in an ecosystem
• Natural selection


  1. Advantageous features help survive

  2. Likely to reproduce

  3. Pass alleles to next generation

  4. Feature becomes more common
• Ionic bond


  Formed by combining metals and non-metals, transfer of electrons

  
• Covalent bond


  Formed between non-metals, sharing of electrons
• Metallic bond


  Force of attraction between metal ions and delocalised electrons