Bonding,10 Flashcards
(36 cards)
Observation during chemical reactions
Observation during chemical reactions:
1. Change in state
2. Fizzing or bubbling
3. Colour change
4. Temperature
5. Sound produced
Why atoms bond became more stable?
Atoms bond to become more stable. To do this they need to achieve “noble gas configuration”
Characteristics about atoms
- atoms can either gain or lose electrons in ionic bonding.
- which they do depends on how many electrons they have on their outer shell.
Metals
Metals lose electrons and form POSITIVE ions.
Non-metals
Non-metals gain electrons and form NEGATIVE ions
Charged particles of ions
Ions are charged particles formed when atom or groups of atoms gain or lose electrons.
Melting points of ionic compounds
Ionic compounds have high melting points and boiling points
Electrostatic forces between ions are:
Strong electrostatic forces between ions.
Ionic atoms are…
Brittle
When ionic compounds conduct electricity
Ionic compounds only conduct electricity when melted ( related to liquid state ) or dissolved in a solution.
Why ions needs to be free
Ions need to be free to move and carry charge
Writing formula
Group 1 => +1 Group 4 => -3
Group 2 => +2 Group 5 => -2
Group 3 => +3 Group 6 => -1
Covalent molecules, state of matter
Simple covalent molecules are liquid or gas at room temperature, eg water, methane and oxygen. They have low melting and boiling points.
Covalent bond
Covalent bond = shared pair of electrons
Covalent compounds has weak…. and strong…..
Weak intermolecular forces, which require little energy to break.
Strong covalent bond ( requires lots of energy to break)
Polymers
Polymers are very large molecules made when hundreds of monomers join together to form long chains.
Plastic
Plastics are synthetic polymers that can be shaped by heat a pressure.
State of matter of plastic
Plastics are solid at room temperature. They have high melting and boiling points.
Monomers
Polymers are made of monomers.
No longer has double bond as this has broken to join monomer together.
Size, type of bonding, intermolecular, conductor of electricity, state at room temperature, POLYMER
Size:
large molecules.
Type of bonding:
strong covalent bonding within chains
Intermolecular forces:
weak intermolecular forces of attraction between small molecules.
Conductor of electricity:
poor conductor of electricity
State at room temperature:
solid at room temperature
Size, type of bonding, intermolecular, conductor of electricity, state at room temperature, SIMPLE MOLECULE
Size:
small molecules
Type of bonding:
strong covalent bonding within small molecules
Intermolecular forces:
many weak intermolecular forces of attraction.
Conductor of electricity:
poor conductor of electricity
State at room temperature:
often a gas or liquid at room temperature
Diamond and Graphite are….
Diamond and Graphite are allotropes of carbon, which are different forms of the same element it is the arrangement of atoms that is responsible but the different properties.
Graphite - giant covalent
- each carbon covalently bonded to 3 others.
- 1 delocalised electron free to carry charge ( electrons).
- weak intermolecular forces between layers, easily broken, so layers slide (pencils).
- high melting points ( strong covalent bonds ).
- uses: pencils, lubricant, electrodes.
Diamond - giant covalent
- each electron covalently bonded to 4 others.
- no free electrons, so does not conduct electricity.
- hard substance: strong covalent bonds.
- high melting point: strong covalent bonds require lots of energy to break.
- uses: jewellery, cutting tools.
