Practise Questions

• Elements with similar properties are found in the same group on the periodic table.
• The periodic table is organised by increasing atomic number
• Why does iodine not react with sodium bromide solution?

  Iodine is less reactive
• What are nanoparticles?

  Very small
• Why did Mendeleev leave gaps in his periodic table?

  For undiscovered elements
• How do the boiling points of the halogens change down the group from fluorine to iodine?

  Increase
• Why does chlorine displace bromine from sodium bromide?

  Chlorine is more reactive than Bromine
• Suggest which halogen could react with sodium chloride solution to produce chlorine.

  Fluorine
• What evidence did Mendeleev use to decide that the alkali metals should be in the same group?

  Similar properties
• Describe how the elements in the modern periodic table are arranged in terms of protons

  In order of atomic number
• Describe how the elements in the modern periodic table are arranged in terms of electrons

  elements in same group have same number of electrons in the outer shell
• State two properties of transition elements that make them more useful than alkali metals for making water pipes.

  Stronger and less reactive
• Describe and explain the trend in reactivity of the alkali metals (Group 1).

  Reactivity increases going down the group as outer electron is further from nucleus

  less attraction between outer electron and nucleus therefore outer electron lost more easily
• Write down two differences you would see between the reactions of potassium and lithium with water.

  Potassium reacts and bubbles faster
• Newlands’ periodic table was not accepted by most chemists in 1866. Suggest reasons why.

  Some boxes contain two elements

  Groups contain elements with different properties

  Newland wasn’t well known so his idea wasn’t accepted
• In Newlands’ periodic table, the elements lithium, sodium and potassium are grouped together. Give two properties of these elements which support the idea that they should be grouped together.

  Reacts with water

  Releases gas
• What are elements organised in?

  Relative atomic number
• What is Sodium (Na)?

  an alkali metal
• what is Nickel (Ni)?

  Transition metal
• Transition elements have similar properties. Explain why, in terms of electronic structure.

  Have same number of electrons on outer shell as inner shell is being filled
• explain why sodium is more reactive than lithium.

  Sodium loses one outer electron more easily as outer electrons further from the nucleus in sodium because forces to hold outer electron are weaker in sodium
• Transition elements have similar properties even though they are not in the same group explain why.

  electrons fill an inner shell usually the same number of outer electrons

   
• Why were Mendeleev's ideas accepted Elements with properties predicted by Mendeleev were discovered and filled the gaps.

  Later on knowledge of isotopes made it possible to explain why the order based on atomic weights was not correct. His prediction came to be true