C2 Flashcards
What is an ion?
Charged particles can be made of single atom (Cl-) or group (NO3-)
metal= lose= +, non-metal= gain -
Why do atoms try to gain a full outer shell?
- Lose or gain electrons to gain full outer shell
- Full outer shell called stable atomic structure it is a very stable element
Groupo 0= full outer shell
Draw the half eqation for Na when forming an ion
group 1
Na-> Na(=) + e(-)
loses 1 electron
Draw the half eqation for O when forming an ion
Group 6
O+ 2e(-)->O^(2-)
What is ionic bonding?
- Metal+ Non-metal react together
- Metal becomes positive +
- Non-metal becomes negative -
- There are strong electrostatic forces for attraction between the oppositly charged ions= ionic bond
Draw a dot and cross digram for Magnesium chloride (MgCl2)
What is the structure and forces of ionic compounds?
- Giant ionic lattice
- Ions are closely packed in regular lattice arragment
- Very strong electrostatic forces of attraction between the ions in all directions
What are the properties of ionic compounds? Justify why.
- High **melting **and boiling points-> strong bonds between ions require lots of energy to overcome
- Cann’t conduct when solid-> ions are held in place
- Can conduct when molten-> ions free to move= carry electric current
- ** Can conduct** when dissolved in water-> ions are seperate and free to move in soltion=carry current
What is the empirical formular of the ionic compound below?
What is covalent bonding?
- Non-metal + Non-metal bond bond together sharing electrons (outer shell) to make colavlent bonds
- positivly charged nucli of bonded atoms are attracted to shared pair of electrons by electrostatic forces= strong covalent bonds
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Draw the dot and cross digram to show the bonding in NH3
What does the dot and cross digram show?
What are the limitations of the dot and cross digram?
+dot and cross show ere each electron comes form
+ good for showing large molecules
- - Dosn’t show relative sizes of the atoms or how they are arraged in a space
- Dosn’t show the 3D structure of the molecule or
£d ball and stick digrmas can get very confusing
What is the bonding and structure of simple molecular subsances?
Molecules containg a few atoms joined together by covalent bonds
What is the bonding and structure of Hydrogen?
- 1 electron, one more needed to complete the first shell
- Bonds to form single covalent bonds e.g with hydrogen
- Simple molecular
What is the bonding and structure in Nitrogen?
- Needs 3 more electrons
- 2 nitrogent atoms shre 3 pairs of electrons
- Triple bond
- Simple molecular
What are the properties of simple molecular substance? Why is this?
Bonding:
* Substances containing covalent bonds usally= simple molecular structure
* Atoms within moleculs held together with very strong covalent bonds
* However…….. forces of attraction between molecules ( intermolecular) forces are very weak
Properties:
* Melting point is very low-> Only need to break feeble intermolecular forces not covalent= moleculs are easly parted
* Most molecualr substances are gass at room temp ( oxygen).
* Don’t conduct electrity-> arnt charged ions= no free elctrons/ions
What happens to the properties of a simple molecular subtance as it gets bigger?
- Bigger= strength of the intermolecular forces increase=> more energy needed to break them=> increased melting and boiling points
What is a polymer? What kind of bonding has it got?
- Giant covalent substance
- Lots of small units linked together to form a long molecule with reapeating sections
- All atoms in polymer joinged by strong covalent bonds
Whta re the properties of polymers and explain them.
- Solid at room temp->Intermolecular forces bewtween molecules are larger then simple covalent=> more energy needed to break them.
- Low melting and boiling points-> intermolecular forces are weaker thne ionic + covalent= lower boiling points than ionic/ giant compounds
What are the general properties and structure of Giant covalent structures?
- All atoms are bonded to each other by strong covalent bonds
- Very high melting and boiling points= lots of energy needed to break the covalent bonds between atoms
- Don’t conduct electrity->( even when molten) Don’t contain charged particels (some exceptions).