Bonding

Define ionic bonding
When positive and negative ions are held together by electrostatic attraction
1 of 32
What form do most ionic substances take and describe it
Giant lattice structure, which is the same basic unit repeated in a regular structure
2 of 32
When can an ionic substance conduct electricity?
When it is molten or dissolved as the ions are free to move and carry a charge
3 of 32
Why do ionic substances have high melting points ?
Lattices are held together by lots of strong electrostatic forces which need a lot of energy to break
4 of 32
What property of water allows it to dissolve ionic substances?
Water is a dipolar molecule
5 of 32
Define covalent bonding
Two atoms share e- to fill both outer shells & held together electrostatically
6 of 32
What is a giant covalent structure ?
Huge networks of covalently bonded atoms
7 of 32
Whats another term for giant covalent?
Macromolecular
8 of 32
Name an element that forms two giant covalent substances and name these structures
Carbon & graphite + diamond
9 of 32
Name the three properties of graphite
Weak layers, free delocalised electrons and low density
10 of 32
Why is diamond the hardest substance in the world?
Each carbon atom is covalently bonded to four other carbon atoms in a tetrahedal shape
11 of 32
Name three properties of diamond
Extremely hard so used for tools, vibrates easily so used as a thermal conductor & it cannot conduct electricity
12 of 32
Define coordinate bonding
When an atom donates a pair of electrons to a central atom, represented by an arrow
13 of 32
Describe electron repulsion theory
Electrons are negatively charged so electron pairs repel each other, pairs form far away from each other as possible & this determines the shape
14 of 32
What is the difference between wedge and broken line notation
Wedges show bonds that are protruded and broken lines show bonds that go inwards
15 of 32
Name the three things you need to know to determine shape
Central atom, number of bonding pairs & number of lone pairs
16 of 32
Define electronegativity
An atom's ability to attract the electron pair in a covalent bond
17 of 32
What is the most electronegative element
Fluorine - 4 on the Pauling Scale
18 of 32
What makes a bond polar?
In a covalent bond between two atoms of different electronegativities, the bonding electron will be pulled towards the more electronegative atom
19 of 32
What determines the strength of polarity?
The greater the difference in electronegativity between the atoms, the more polar the bond
20 of 32
What type of intermolecular force do polar molecules have?
Permanent dipole-dipole
21 of 32
What is an intermolecular force?
Forces between molecules
22 of 32
What intermolecular force is found between all atoms and molecules?
Van der Waals
23 of 32
Explain how van der waals are formed?
Electrons move quickly and are likely to build up in one part of an atom, causing a temporary dipole. This dipole causes another dipole on a neighbouring atom and each atom then has a dipole in a domino effect
24 of 32
Why do van der waals prefer unbranched molecules?
Long straight molecules can lie close, the closer the molecules the stronger the forces
25 of 32
What properties do molecules with lots of van der waals have?
Large electron clouds, stronger molecules and higher boiling/melting points
26 of 32
What is the strongest intermolecular force and why?
Hydrogen bonding as it contains very electronegative elements making it very polar
27 of 32
What three elements does hydrogen form hydrogen bonds with?
Fluorine, nitrogen and oxygen
28 of 32
What is metallic bonding?
Positive metal ions are attracted to the delocalised negative electrons, forming a lattice of closely packed cations in a sea of delocalised electrons
29 of 32
Why do metals have high melting and boiling points?
Because of the strong electrostatic attraction between the cations and the delocalised sea of electrons
30 of 32
What makes metals good thermal and electrical conductors?
Their ability to pass kinetic energy and to carry a current due to their delocalised electrons
31 of 32
Why are simple covalent compounds easier to melt than giant covalent substances?
To melt a simple structure you just have to break its intermolecular forces only but for giant structures the covalent bonds have to be broken too
32 of 32

Other cards in this set

Card 2

Front

What form do most ionic substances take and describe it

Back

Giant lattice structure, which is the same basic unit repeated in a regular structure

Card 3

Front

When can an ionic substance conduct electricity?

Back

Preview of the front of card 3

Card 4

Front

Why do ionic substances have high melting points ?

Back

Preview of the front of card 4

Card 5

Front

What property of water allows it to dissolve ionic substances?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Bonding & shapes resources »