Groups In The Periodic Table

Question 1

What are Alkali Metals and their properties?

Answer 1

• Common names for the group 1 elements.
• Group 1 elements all have one electron in their outer shell.
• they are much more reactive.
• they are softer.
• they have lower melting and boiling points.

Question 2

What is the reactivity of Group 1 elements?

Answer 2

• they readily lose single outer electron to form stable 1+ ion.
• reactivity INCREASES down group 1 as outer electron is further from nucleus and more easily lost.
• alkali metals react vigorously with water to make alkalis:
  Alkali metal + water —> metal hydroxide + hydrogen

Question 3

What is the reactivity and properties of Group 0 elements?

Answer 3

Group 0 elements- non-metals with full outer shells of electrons also called noble gases.
Full outer shells are very stable, so these elements are inert (unreactive).
All Group 0 elements are colourless monatomic gases at room temperature.
As you go DOWN group 0 density increases and melting and boiling points increases.

Question 4

What are the Group 7 elements?

Answer 4

Halogens- the non-metal elements in group 7.
The halogens exist as diatomic molecules- two atoms joined by a covalent bond.
Halogens and their appearance at room temperature:
Chlorine —> green gas (turns damp blue litmus paper white)
Bromine —> red-brown liquid which gives off orange vapour
Iodine —> dark grey solid which gives off purple vapour

Bromines and iodines different states shows melting and boiling points increase down the group.

Question 5

What is the reaction of Group 7 elements?

Answer 5

Halogens have seven outer shell electrons- they gain one electron to form a stable 1- ion.
Reactivity decreases down Group 7 as outer shell is further from nucleus so it’s harder to gain an electron.
Metal + halogen —> metal halide
Hydrogen + halogen —> hydrogen halide
Hydrogen halides form acidic solutions when dissolved in water.