paper 2

• What is the periodic table used for in chemistry?

  It shows elements with similar properties
• What are the columns of the periodic table called?

  Groups
• What are the rows of the periodic table called?

  Periods
• How many electrons do group one elements have in their outer shell?

  One electron
• How many electrons do group two elements have in their outer shell?

  Two electrons
• What do elements in the same period have in common?

  Same number of electron shells
• What is a key property of group one metals?

  They react with oxygen, chlorine, and water
• How does reactivity change down group one?

  Reactivity increases down the group
• Why does reactivity increase down group one?

  Atoms increase in size and more shells exist
• What happens to the outer shell electron as you go down group one?

  It is further away from the nucleus
• What is the general reaction of group one metals with water?

  Metal plus water makes metal hydroxide plus hydrogen
• What do alkaline metals form when they react with water?

  Metal hydroxide and hydrogen gas
• What is observed when alkaline metals react with water?

  Fizzing and solid metal disappearing
• What group are halogens found in?

  Group seven
• How many electrons do group seven elements have in their outer shell?

  Seven electrons
• What type of molecules do halogens consist of?

  Diatomic molecules
• How does reactivity change down group seven?

  Reactivity decreases down the group
• Why does reactivity decrease down group seven?

  Atoms increase in size and outer shell is further away
• What happens to the melting and boiling points of halogens down the group?

  They increase down the group
• Why do melting and boiling points increase down group seven?

  Molecules increase in size, stronger intermolecular forces
• What are the states of halogens at room temperature?

  • Fluorine: yellow gas
  • Chlorine: yellow-green gas
  • Bromine: red-brown liquid
  • Iodine: gray solid
• What do halogens produce when they react with metals?

  Salts
• What do halogens form when they react with hydrogen?

  Hydrogen halides
• What happens when chlorine reacts with potassium bromide?

  Chlorine displaces bromine
• What happens when chlorine reacts with potassium fluoride?

  No reaction occurs
• What is observed when potassium bromide reacts with chlorine?

  Orange color of bromine in solution
• How do you test for chlorine gas?

  Damp blue litmus paper turns white
• What are spectator ions?

  Ions that do not participate in the reaction
• What is the ionic equation for the displacement reaction of chlorine and potassium bromide?

  Cl₂ + 2 KBr → 2 K + Br₂
• What are the properties of group zero elements?

  Full outer shell, unreactive, monatomic
• How does the boiling point change down group zero?

  Boiling point increases down the group
• What is helium used for due to its properties?

  Used in balloons and airships
• What is argon used for in welding?

  As a shield gas to prevent oxidation
• What is the rate of a reaction?

  Measurement of how quickly reactants are used
• How do you calculate the mean rate of a reaction?

  Quantity of reactant or product divided by time
• What are the units for rate of reaction when measuring mass?

  Grams per second
• What are the units for rate of reaction when measuring volume?

  cm³ per second
• What does a steep curve on a reaction graph indicate?

  High rate of reaction
• What does a shallow curve on a reaction graph indicate?

  Low rate of reaction
• What is the method for measuring change in mass during a reaction?

  Use a balance and record at intervals