Flashcards in C2b Topic 4 - Groups in the Periodic Table Deck (21)
Typical properties of metals
1) They conduct electricity well. This makes them great for making electrical wires.
2) They're malleable - they can be bent and hammered into different shapes. This makes them great for making things like bridges and car bodies.
Properties of transition metals
1) High melting points
2) Form very colourful compounds
3) They also have all the typical properties of metals
Structure of metals that gives them their properties
1) Metals consist of a regular arrangement of atoms held together with metallic bonds.
2) The metallic bonds give the metal a giant structure consisting of positive ions and free electrons. This is because metallic bonds allow the outer electron(s) of each atom to become delocalised (move freely).
3) This creates a "sea" of delocalised electrons throughout the metal, which is what gives rise to many of the properties of metals. For example, the ability of electrons to move freely through the structure makes metals good conductors of electricity.
4) The giant metallic structure and strong bonds mean that metals have extremely high melting and boiling points and are insoluble.
5) They also allow layers of atoms to slide over each other, allowing metals to be bent and shaped. This makes metals malleable.
The alkali metals are soft and have
Low melting points
Group 1 elements react vigorously in
Water to form hydroxides.
When alkali metals react in water this reaction makes an
Alkaline solution (which would change universal indicator to blue or purple)
Metals are on the
Left and middle of the periodic table
As you go down group 1..
The lone electron is in a shell that's further way from the nucleus. As they are further apart, the attraction between the positively charged nucleus and the negatively charged electron decreases. This means the electron is easier to get rid of.
Elements further down group 1 are _______ reactive
Lithium takes longer than sodium or potassium to react, so it's the least reactive. Potassium takes the shortest time to react of these three elements so it's the ________ reactive
The elements in group 1 get more reactive as atomic number __________
The reaction of an alkali metal with water produces
Hydrogen. A lighted splint will indicate the hydrogen by making the notorious "squeaky pop" as the hydrogen ignites.
Group 7 elements are known as the
At room temperature:
Chlorine is... a fairly reactive, poisonous, dense green gas.
Bromine is... a dense, poisonous, orange liquid.
Iodine is...a dark grey crystalline solid.
Halogens react with most metals to form
Halogens can react with hydrogen to form
Hydrogen halides are
Soluble! They dissolve in water to form acidic solutions.
More reactive halogens will displace less reactive ones
1) The higher up Group 7, the more reactive an element is. This is because the outer shell is nearer to the nucleus, so the pull from the positive nucleus is greater which attracts extra electrons more strongly.
2) When halides dissolve in water, the halide ions are free to react.
3) If a more reactive halogen reacts with a solution containing halide ions it will displace the less reactive halogen. This is a displacement reaction.
4) E.g. Chlorine is more reactive than iodine (it's higher up group 7). Chlorine therefore reacts with potassium iodine to form potassium chloride and iodine.
Group 0 elements (the noble gases) are all
Inert, colourless gases
Uses of argon
1) Provides inert atmosphere in filament lamps. As argon is non-flammable it stops the very hot filament from burning away.
2) It can also be used to protect metals that are being welded. The inert atmosphere stops the hot metal reacting with oxygen.