Periodic Trends In Bonding And Structure Flashcards Preview

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Flashcards in Periodic Trends In Bonding And Structure Deck (17)
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1

Metals and non metals on the periodic table

Changeover from metal to non metal takes place on diagonal line
Elements near divide show in between properties, metalloid
More metals than non metals

2

Metallic bonding

Each atom has donated outer shell electrons to a shared pool of delocalised electrons
Cations consist of nucleus, inner electron shells
Cations in fixed positions, maintain metal structure and shape
Delocalised electrons, mobile
Giant metallic lattice

3

Properties of metals

Strong metallic bonds
High electrical conductivity
High melting and boiling points
Insoluble

4

Electrical conductivity of metals

Conduct in solid and liquid states
Delocalised electrons move through structure carrying charge

5

Metallic bonding

Strong electrostatic attraction between cations and delocalised electrons

6

Melting and boiling points in metals

Most have high melting and boiling points
Depends on strength of metallic bonds holding atoms together
High temperatures are necessary to provide the large amount of energy needed to overcome the strong electrostatic attraction between cation, electrons

7

Solubility of metals

Metals do not dissolve
Any interactions would lead to a reaction rather than dissolving

8

Giant covalent structures

Boron, carbon, silicon
No intermolecular forces, network of strong covalent bonds only

9

Giant covalent lattice

Billions of atoms are held together by a network of strong covalent bonds

10

Giant covalent properties

High melting and boiling point
Insoluble in almost all solvents
Non conductors except graphite, graphene

11

Melting and boiling points of giant covalent structures

High melting and boiling points
Covalent bonds are strong, high temperatures needed to break them

12

Solubility of giant covalent structures

Insoluble in almost all solvents
Covalent bonds holding atoms in the lattice are too strong to be broken

13

Electrical conductivity of giant covalent structures

Non conductors in diamond, silicon
All 4 outer shell electrons involved in covalent bonding, non available for conducting, electricity
Graphene, graphite have free electrons, conduct electricity

14

Giant covalent lattice

Billions of atoms are held together by a network of strong covalent bonds

15

Graphene

Single layer of graphite
Hexagonally arranged carbon atoms linked by strong covalent bonds, 1 free electrons

16

Graphite

Parallel layers of hexagonally arranged carbon atoms, stack of graphene layers
Strong covalent bonds and weak London forces, 1 spare electron

17

Periodic trends in melting points

Melting point increases from Group 1-14(giant metallic, giant covalent)
Sharp decrease in melting point between Group 14-15
Melting points comparatively low from Group 15-18 (simple molecular)