chemistry

• what is a metallic bond


  metal and metal and has positive ions ( latice) and a sea of delocalised electrons
• what is an ionic bond


  metal and non metal and they give and take electrons
• what is an convalent bond 


  non metal and non metal and they have a shared pair of electrons
• what is group 7 called?

  Halogens
• What is group 1 called?

  Alkali metals
• what is group 8 called?

  Noble gases
• what do the group number on the periodic table represent?

  number of electrons on the outer shell
• What do the periods mean in the periodic table?

  Number of shells
• What does exothermic mean?


  energy exits to the surroundings.
• what does endothermic mean?


  Take in energy from the surroundings
• give 2 examples of exothermic reactions?

  combustion, neutralisation
• give 2 examples of endothermic reactions?


  electrolysis, thermal decomposition
• What is the definition for activation energy?


  The energy produced as the reaction takes place
• On a reaction profile, what does the height of the hump represent?

  The energy change
• How do you calculate the number of neurons 


  take away the atomic number from the mass number
• what does the atomic number mean?

  number of protons and electrons
• what does the mass number mean?

  the number of protons and neutrons
• why does the further you go down group 1 get more reactive?

  because the outer electron gets further from the nucleus as more shells so weaker attractions so more easily lost
• what are electrodes made out of?

  carbon
• what are electrodes?


  rode that conduct electricity and they come in pairs
• what side is non metals on a periodic table

  left
• what did mendeled discover

  discovered mondern periodic table