C2 - Bonding, Structure and the properties of Matter Flashcards
Formation of ions, ionic bonding, ionic compounds, covalent bonding, simple molecular structures, allotropes of carbon, metallic bonding, states of matter, changing state, nanopartciles, uses of nanoparticles. (68 cards)
Formation of ions -
What are ions?
Charged particles
Formation of ions -
When are ions made?
When electrons are transferred
Formation of ions -
What happens when metals form ions?
lose electrons form + ions
Formation of ions -
What happens when non metals form ions?
Gain electrons form - ions
Ionic Bonding -
What is ionic bonding?
- Metal + non metal react.
- metal lose electron form positive ion
- non metal gain electrons form negative ions.
- opposite charge of ions are strongly attracted by electrostatic forces (called an ionic bond)
Ionic Bonding -
What is the name of the diagram used to represent ionic bonding?
dot and cross diagrams
Ionic Bonding -
What don’t dot and cross diagrams show?
- structure of compound
- size of ions
- how arranged
Ionic compounds -
What is the structure of an ionic compound?
Giant ionic lattice
Ionic compounds -
What is the structure in a giant ionic lattice?
-regular lattice
- strong electrostatic forces of attraction between oppositely charged ions
Ionic compounds -
What are the properties of ionic compounds?
- high melting and boiling point (many strong bonds between ions)
- when solid can’t conduct electricity
- when melted, ions free to move and carry electrical charge
- some dissolve in water (ions separate and free to move in solution so carry electrical charge)
Covalent bonding -
When does covalent bonding occur?
when non metals bod together + share pairs of electrons
Covalent bonding -
Why are covalent bonds very strong?
Positive nucleus of atoms attracted to the shared pair of electrons by electrostatic forces.
Covalent bonding -
What are the different ways of displaying covalent bonds?
- Dot and cross diagrams - electrons drawn in the overlap of the electron shells between those atoms.
- Displayed formula - shows covalent bonds as single lines between atoms
- 3D model - shows atoms, covalent bonds and their arrangement
Covalent bonding -
What are the + and - of the ways covalent bonds are displayed?
- Dot and cross diagrams:
+ show which atoms electrons come from - don’t show relative size of atoms
- how atoms arranged
- Displayed formula:
+ show how atoms connected in large molecules - don’t show 3D structure of molecules
- don’t show which atoms electrons come from
3D model:
+ shows atoms
+ shows covalent bonds and arrangement in space
- confusing for large molecules
- don’t show where electrons come from
Simple molecular substances -
What are simple molecular substances made up of?
Molecules containing a few atoms joined together by covalent bonds.
Simple molecular substances -
What are common examples of simple molecular substances?
-Hydrogen: 1 electron, one more to complete, form single covalent bonds
- Oxygen: need two more electrons, make double covalent bonds
- Methane: Carbon 4 outer shell electrons, forms 4 covalent bonds with hydrogen atoms
- Chlorine: 1 more electron, 2 chlorine atoms share pair electrons form single covalent bond
- Nitrogen: 3 more electrons, share 3 pairs electrons, triple covalent bond
-Water: oxygen shares pair electrons with two hydrogen atoms, form two single covalent bonds
- Hydrogen Chloride: Both atoms need 1 more electron.
Simple molecular substances -
Properties of simple molecular substances:
- covalent bonds
- very strong covalent bonds
- force attraction between molecules very weak.
- to melt/ boil need break feeble intermolecular forces not covalent bonds
- low melting and boiling points
- gases or liquids at room temp
- don’t conduct electricity (as not charged so no free electrons)
Polymers and Giant Covalent Structures -
What are polymers?
Long chains of repeating units
Polymers and Giant Covalent Structures -
How are atoms in polymers joined?
Strong covalent bonds
Polymers and Giant Covalent Structures -
What do you draw when drawing a polymer?
The repeating unit (shortest repeating section)
Polymers and Giant Covalent Structures -
How do you find the molecular formula of a polymer?
Write molecular formula of repeating unit in brackets and put an n outside
Polymers and Giant Covalent Structures -
Why are polymers solids at room temperature?
Intermolecular forces between molecules large so more energy to break bonds
Polymers and Giant Covalent Structures -
Why is the boiling point of a polymer lower than an ionic or covalent compound?
Intermolecular forces weaker between molecules
Polymers and Giant Covalent Structures -
What are giant covalent structures?
Macromolecules