Bonding, structure and properties of matter (1) Flashcards
What is ionic bonding?
Transfer of electrons between a metal atom to a non-metal atom
What are the properties of ionic compounds?
-High melting and boiling point
- Conduct electricity (when melted or dissolved in water)
- High strength bond
- Transfers electrons
- Form ions
- Regular
Complete:
Metals normally form ions which have a ________ charge, which non-metals normally form ions which have a _____ charge
Metals form positive ions
Non-metals form negative ions
Why do ionic compounds have a high melting and boiling point?
The bonds are really strong, so it requires a lot of energy to be broken
Why do ionic compounds need to be molten or in aqueous solution to conduct electricity?
Because when they are in solid form, everything (electrons/ions) is fixed, so to conduct energy particles need to be free to move, and that what happen when they are in molten form
Formula for Hydroxide ion
OH(-)
Formula for Sulfate ion
SO4(2-)
Formula for Nitrate ion
NO3(-)
Formula for Carbonate ion
CO3(2-)
Formula for Ammonium ion
NH4(+)
What is Covalent bonding?
Transfer of electrons between two non-metal elements
What are simple molecular substances?
Small molecules, on which the atoms in the molecule are joined by strong covalent bonds, but between the molecules there are weak intermolecular forces
What are Giant covalent structures?
Millions of atoms arranged in a regular lattice, where all the atoms are joined by covalent bonds, so they are really strong
IN SIMPLE MOLECULAR SUBSTANCES THE ATOMS WITHIN EACH MOLECULE WILL BE STRONGLY BONDED TOGETHER
TO MELT A SIMPLE MOLECULAR SUBSTANCE WE DO NOT BREAK THE COVALENT BONDS, INSTEAD WE ONLY NEED TO BREAK THE WEAK INTERMOLECULAR FORCES
Do we need high or low temperatures to melt or boils simple molecular substances?
Low temperatures
AS BIGGER THE ATOMS IS THE STRONGER IS THE INTERMOLECULAR FORCE
MORE ENERGY REQUIRED TO BREAK
Why simple molecular substances do not conduct electricity?
There are no free electrons, and the molecules do not have a charge
Give 3 examples of giant covalent structures
- Diamond
- Graphite
- Silicon Dioxide
Properties of giant covalent structures:
- Very strong
- High melting and boiling point
- Do not conduct electricity (even when molten)
What is a allotrope?
Different structural forms of the same element in the same physical state
Properties of Diamond:
- Each Carbon atom is covalently bonded to 4 other carbon atoms
- Strong
- Really high melting point
- Do not conduct electricity because there are no free electrons or ions
Properties of graphite:
- Each carbon atom is bonded to other 3 carbon atoms
- The atoms are arranged in flat sheets, which are then arranged on the top of one another (These individual layers are held together weakly because there are no covalent bonds between them)
-Relatively soft - High boiling point
- As carbon can hold up to 4 other carbon atoms and in graphite it is just bonded with 3, there is 1 spare electron for each carbon atom, which is delocalised, allowing graphite to conduct electricity and heat.
What are the layers from graphite known as?
Graphene
What can we use fullerenes for?
- Scientists can form spheres around other molecules (act like a cage) - for medicine
- Industrial catalyst
