Topic 1 - atomic structure

• What are compounds made of?

  Compounds are made of atoms that join together.
• How do atoms join together to form compounds?


  Atoms join together by giving, taking, or sharing electrons.
• What happens to the nuclei of atoms when a bond is made?

  The nuclei of the atoms are not affected when a bond is made.
• What is required to separate the original elements of a compound?

  A chemical reaction is needed to separate the original elements of a compound.
• What type of bonding occurs in a compound formed from a metal and a non-metal?

  Ionic bonding occurs in a compound formed from a metal and a non-metal.
• What is the maximum number of electrons that the first shell can hold?

  2 electrons
• What is the maximum number of electrons that the second shell can hold?

  8 electrons
• How do you determine the electronic structure of an element?

  By following the electron shell rules based on the number of protons.
• What is the electronic structure of nitrogen, which has an atomic number of 7?

  2, 5
• What is the electronic structure of magnesium, which has an atomic number of 12?

  2, 8, 2
• What are the electronic structures of the first 22 elements of the periodic table?

  • You can calculate them using the electron shell rules.
  • The first shell holds 2 electrons, the second holds 8, and the third can hold 8
• What was the primary method of classifying elements in the early 1800s?

  By atomic weight.
• Why were early periodic tables incomplete?

  They were arranged by atomic weight without considering properties.
• How did Dmitri Mendeleev improve the periodic table?

  He arranged elements by atomic weight and properties, leaving gaps for undiscovered elements.
• What did Mendeleev predict about undiscovered elements?

  He predicted their properties based on gaps in his periodic table.
• What confirmed Mendeleev's approach to arranging elements?

  The discovery of isotopes.
• What are transition metals and where are they located in the periodic table?

  Transition metals are found in the center of the periodic table.
• What are some properties of transition metals?

  They are good conductors of heat and electricity, dense, strong, and shiny.
• How do metals and non-metals differ in terms of ion formation?

  Metals form positive ions, while non-metals do not generally form negative ions.
• What is the significance of the outer shell electrons in determining reactivity?

  The number of outer shell electrons determines how elements will react.
• What happens to the reactivity of Group 1 elements as you go down the group?

  Reactivity increases as you go down the group.
• What happens to the reactivity of Group 7 elements as you go down the group?

  Reactivity decreases as you go down the group.
• What are the physical properties of metals?

  Metals are strong, malleable, good conductors of heat and electricity, and have high boiling and melting points.
• What are the physical properties of non-metals?

  Non-metals are dull, brittle, may not be solids at room temperature, do not conduct electricity, and often have lower density.
• What is the role of metallic bonding in metals?

  Metallic bonding gives metals their characteristic properties such as strength and conductivity.
• What is the significance of the periodic table in chemistry?

  The periodic table helps to see patterns in properties and predict how elements will react.
• What is the electronic structure of aluminium, which has an atomic number of 13?


  2, 8, 3
• What is the electronic structure of argon, which has an atomic number of 18?

  2, 8, 8
• when do you use filtration ?


  • if your product is an insoluable solid that needs to be seperated from a liquid reaction mixture
  • can be used in purification as well (e.g. sperateing solid impurities in the reaction mixture
• the 2 ways to seperate soluable solids from solutions 


  • evapouration
  • crysatlisation
• Evapouration :


  • pour solution into the evapourating dish
  • slowly heat solution, the solvent will evapourtate and the solution will get more concentrated. eventually crystals will start to form
  • keep heating the dish until all you have left is dry crystals
• Crystallisation 


  • pour solution into an evapourating dish and heat gently
  • some of the solvent will evapourate and the solution will get more concentrated
  • once some of the solvent has evapouated or when you see crystals start to form, remove the dish from the heat and leave solution to cool
  • the salt shoul start to form crystals as it becomes insoluable in the cold, highly concentrated solution
  • filter the crystals out of the solution and leave them in a warm place to dry
• what is simple distilation used for 


  seperating out a liquid from a solution
• problem with simple distillation :


  can only be used to seperate liquids with very different boiling points
• Simple distilation 


  • solution is heated- the first part of the solution that has the lowest boiling point evaporates first
  • the vapour is then cooled, condenses and is collected
  • the rest of the solution is left behind in the flask
• when is fractional distilation used?

  if you have a mixture of liquids with similar boiling points
• Fractional distilation 


  • pour mixture into a flask and stick a fractioning column on top
  • as the liquids have different boiling points they will evapouate at different temperatures
  • liquid with the lowest BP evaporates first
  • when the temperature on the thermometer is the BP of this liquid it will reach the top of the column
  • liquids with higher BP may also start to evapourate but they will only get part of the way up before condensing and running back down to the flask
  • when the first liquid is collected you increase the temp until the next one reaches the top
• in a fractioning coloumn the top is the coolest and the bottom is the warmest as it is heated from the bottom
• group one are called...

  alkali metals
• group 7 are called ...


  halogens