EL 8 Flashcards
(14 cards)
Properties Of Metals
- Malleable
- Magnetic
- Ductile
- Thermal Conductor
- Electrical conductor
- HBP + HMP
- High Density
- Shiny
How Are Metallic Atoms Bonded Together?
Metallic Bonding - The outer electrons of metals become delocalised and are free to move in a ‘sea of delocalised electrons.’ The positively charged metallic cations are attracted to the delocalised negatively charged electrons.
Unusual properties compared to transition metals
They are soft - easy to cut (bcos weak metallic bonding)
They are weak - break easily
They have low melting points (bcos of the 1/2 electron(s) on outer shell)
Why do elements in group 1 and 2 lose electrons?
- Outer electrons are removed to achieve a full outer shell
- (They are found in their atomic state when they are stored in oil in the labs)
What is a Salt?
A chemical compound consisting of an ionic assembly of positively charge cations and negatively charged anions.
In the structure of an ionic lattice.
Group 1 and 2 metals are known as alkaline metals and alkaline earth metals (respectively), but why?
When they react w/ water, they both react to make a metal hydroxide and hydrogen gas.
What happens when group 1 and 2 metals react w/ Oxygen?
They produce oxides.
What happens when group 1 and 2 metals react w/ chlorine?
The produce chlorides.
Why does reactivity of group 1 and 2 metals increase when going down the group?
- bcos there is a greater no. of shells as you go down the group. There is an increased distance from the outer electron from the positively charged nucleus, hence the attraction between them is weaker and it requires less energy to lose the outer electron.
- bcos electron shielding - where the inner shells shield the outer electron from the attraction of the nucleus.
The no. of protons does increase but this is superseded by the number of shells and the distance the outer electron is in comparison to the positively charged nucleus.
Why are group 1 metals more reactive than group 2 metals?
They only require 1 electron to be removed but group 2 requires 2. This requires more energy, hence why they are less reactive.
Group 2 oxides + water –>
Hydroxide
Group 2 oxides + acid –>
Salt + water
Group 2 Hydroxide + Acid –>
Salt + Water
Group 2 Hydroxide + water –>
Dissolve in water to form soluble ions
– Mg(OH)2 —> Mg2+ + 2OH-
