3.1.3 Bonding Flashcards
Substance
Made out of one repeating unit
What is a mixture
Made out of different repeating units
What is a compound?
A substance containing atoms of more than one element
What is the electron sea model
Metals are made up of a lattice of cation surrounded by a sea of delocalised electrons.
How do delocalised electrons allow a metal to conduct electricity
They are freely moving throughout the metal and are charged
What is metallic bonding?
The electrostatic attraction between cations and delocalised electrons.
Why are metals malleable and ductile?
The layers of cations can slide over each other without breaking any metallic bonding
Why do metals have high melting and boiling point?
They have strong electrostatic attraction between the cation and delocalised electrons
Why does the melting point of metals increase across a period?
Group 1 metals form + charges
Group 2 metals form 2+ charges
Group 3 metals form 3+ charges
This means that as they go across the melting point increases as they form metallic bonding with more higher charged cations
Down a group, the melting point….
Decreases.
This is because the size of the cations increase which means theres a larger distance between the nucleus and outer electrons so there are weaker attraction
State and explain the general trend in melting point if the period 3 metals.
Across a period the charge of the cation increases, so there is a stronger attraction between the cation and delocalised electrons.
This stronger attraction means the strength of the metallic bonding increases across a period and so therefore the melting point too
What are positively charge ions called?
Cations
What are negatively charged ions called?
Anions
Define ionic bonding.
Electrostatic forces of attraction between oppositely charged ions formed by electrons transfer
What are the simplest ion
a single atom which have either lost/gain electrons so that they’ve got a full outer shell.
What are ionic crystals called?
giant lattice of ions.
Is the melting a point of ionic compounds high or low?
High
Charge of sliver
+
Charge of Zinc
2+
Charge of iron
2+/ 3+
Charge of copper
+\2+
Charge of lead
2+\4+
Sulfate ion and charge
So4(2-)
Nitrate ion and charge
NO3(-)
Manganate ion and charge
MnO4(2-)
Phosphate ion and charge
PO4 (3-)
Hydrogen carbonate ion and charge
HCO3(-)
Hydroxide ion and charge
OH(-)
What state can ionic compounds conduct electricity
Liquid or molten as they are free to move around.
Why do ionic compounds have high melting and boiling points?
There is a strong attraction between the cations and anions
The larger the charge between two charges the ___ the ionic bonding is
Stronger
The ____ the distance between two ions the _____ the ionic bonding
- Larger
- Weaker
Down a group the size of ions…
Increases
When are covalent bonds formed
When atoms share a pair of electrons
Examples of micromolecular structures
- Graphite
- Diamond
what is the structure of graphite?
Carbon is arranged in sheets of flat hexagon. The fourth outer electron of each carbon atom is delocalised.
what property graphite used as dry lubricant and pencils
the weak bonds between the layers in graphite are easily broken, so the sheets can slide over.
explain why graphite is a good electrical conductor.
the delocalised electrons in graphite aren’t attached to any carbon. Therefore, are free to move and can conduct electricity.