4.1 reactivity and characteristics of group 1,7,8- chemistry

• properties of group 1 metals:

  metals are expected to be strong, have high density and a high melting point. However group 1 metals are soft with low density and low melting points.
• are group 1 metals reactive?

  they are much more reactive than other metals. They react vigorously with water, oxygen and group 7 element such as chlorine.
• does reactivity increase up or down with group 1?

  reactivity goes down.
• what are some trends in group 1 as you go down the group.

  melting and boiling points decrease.
• what properties make alkali metals so reactive?

  -having one electron in their outershell making it easier to react and become stable as only one needs to be lost.
• what happens when alkali metals lose their electron in their outer shell?

  they become a positive one ion.
• what happens to the radius of group 1 elements as you go down?

  it increases meaning:

  • positive nucleus is further away which holds it in place
  • Increased distance weakens the attractive force meaning the electron can be lost more easily
• what do alkali metals form and why?

  ionic compounds with non metals, so both of then have full outer shells, then because they are oppositely charged they‘ll be attracted to eachover by electrostatic forces in this case we call it an ionic bond.
• what happens when alkali metals are put in water, heated in chlorine gas and oxygen

  water- reacts vigorously producing a metal hydroxide and hydrogen gas

  heated in chlorine gas- reacts vigorously producing white metal chloride salts

  oxygen-form metal oxides however the type of oxide they form depends on the particular metal
• properties of halogens:

  all quite dangerous for example:

  Florine- poisonous yellow gas being very reactive.

  Chlorine-less reactive and a poisonous green gas

  Bromine-brown voltile liquid also being poisonous.

  Iodine- grey solid which can be turned into a poisonous purple vapour as well as it being an antiseptic
• how do halogens come stable?

  become diatomic molecules by sharing electrons which form a covalent bond. Another way they become stable is reacting with other non metals such as carbon or hydrogen.
• what happens to the reactivity, meting and boiling point as you go down the group?

  reactivity decreases

  melting and boiling point increases
• why does reactivity of halogens decrease as you go down the group?

  outershell gets further away from the positive nucleus so the attractive force gets weaker.
• what is displacement reactions?

  A chemical reaction where the more reactive element take the place of another in a compound.
• properties of noble gases:

  Inert- don't react

  colourless gases

  non flammable

  boiling point increases as you go down the group.