Bonding Flashcards
Define Metallic Bonding
The strong electrostatic attraction between positive metal ions and delocalised electrons
Draw this bonding ( metallic )- refer to notes for answer
Hint!
When drawing metallic bonding diagrams:
Always draw at least 6 ions (2 rows of 3)
Work out the charge of the ion (i.e. how many electrons are lost from the atom?)
Draw the correct number of delocalised electrons. (i.e. the sum of all the charges)
The bonding in magnesium is stronger than sodium because …
-Mg has a greater charge of 2+
-Mg has twice as many electrons
-Mg ions are smaller, meaning there is a greater charge density
-The attraction between the Mg2+ ions and the delocalised electrons is stronger
Property of metal: Conductivity
-Good electrical and thermal conductors
-Delocalised electrons are free to carry charge/current
Property of metal:Strength
Strong due to strong electrostatic attraction between + ions and delocalised electrons
Property of metal: malleable and ductile
- Ions can slide over each other in layers
Covalent bond definition
Shared pair of electrons between two atoms
What are the three macromolecules
Carbon, silicon oxide and silicon
Explain the structure of diamond
-Each carbon forms 4 covalent bonds
-Tetrahedral arrangement
- Hard material with high melting point
Doesn’t conduct electricity as no delocalised electrons
Explain the structure of graphite
- layers of carbon atoms, forms 3 covalent bonds
-Delocalised electron to carry charge
-Layers held together by van deer walks
-high melting point due to lots of covalent bonds
Ionic bond definition
Electrostatic attraction between oppositely charged ions
Define coordinate bond
Shared pair of electrons which have both been donated by the same atom
Explain repulsion between BP and no LP
Electron pairs repel as far apart as possible
Define electronegativity
The ability of an atom to attract the pair of electrons in a covalent bond
What factors affect electronegativity
-number of protons
-shielding
-distance from the nucleus
-shared electrons
Define the term dipole- what does it create
Uneven distribution of electron density across a bond- creates a polar bond
Polarity in cl2
Equal distribution of electron charge- same electronegativity, no dipole. No polarity
Polarity in HCL
The Cl atom is more electronegative than H. Uneven distribution of electron charge, creating a dipole and a polar bond
Hydrogen Bonding:How it arises
Very large difference in electronegativity between the two atoms. This creates a strong dipole. There is a strong attraction between the lone pair on the oxygen and the delta + on another molecule
Permanent dipole dipole forces: how it arises
Difference in electronegativity between the atoms. This creates a polar bond, the dipoles don’t cancel out as it is asymmetrical. Attraction between delta - and delta + on another molecule
Induced dipole dipoles: How it arises
Random movement of electrons in a molecule creates a temporary dipole (uneven distribution of electron density). this induces a dipole in another molecule. the delta + on one molecule attracts the delta - on another
