Topic 2 - structure and bonding

Question 1

Name for positive and negative ions

Answer 1

positive - cation
negative - anion

Question 2

Ionic compounds structure

shape, forces, charge

Answer 2

lattice.
oppositely charged ions are attracted into a lattice that gets biggrt until it consists of millions of ions
- non direction forces

Question 3

metallic bonding structure

electrons, forces, bonding, arrangemeny

Answer 3

• each metal loses its valence electron (s)
  these electrons move freely through the kattice between the positively charged metal ions
• strong electrostatic forces of attraction
• 3D lattice with non- directional bonding

Question 4

What state is metal in at room temp ? why?

forces, mp bp

Answer 4

Electrostatic force of attration of the metallic bond is strong and requires a lot of energy to over come. Results in a high melting and boiling point

Question 5

Are metals good conductors of heat and electricity ? why?

electrons

Answer 5

Have electrons that are mobile/ delocalised, which can carry a charge or heat energy through the metal.

Question 6

What is the mobility of metals ? why?

electrons.

Answer 6

Surrounded by a sea of delocalised electrons. When the slightly positive metal atoms are deformed (molded or pulled into wires), the free moving electrons flow around them, shielding the slightly positive atoms from each other.

Question 7

What is the state of covalent molecualr structures at room temp? why?

mp bp, bonds,energy

Answer 7

• Liquid or gases at room temperature
• Low melting and boiling points
  Substances are made up of simple molecules. Atoms are joined by covalent bonds; molecules have weak intermolecular force.
  Not much energy is needed to separate the molecules from each other.

Question 8

What is the solubility of covalent molecular structures ?

Answer 8

• Not many soluble in water
• Soluble in organic solvents
  Covalent molecular substances dissolve in covalent molecular substances

Question 9

Are covalent molecular substances good conductors ? why?

particles, charges

Answer 9

Cannot conduct
no mobile charged particles

Question 10

What is the state of ionic substances at room temperature?Why?

mp bp, arrangement, attraction, energy

Answer 10

• Crystalline solids at room temperature
• High melting/ boiling points
• Regular arrangement of ions in a lattice (positive, negative ions)
• Ions are attracted to each other by strong electrostatic force of attraction.
• Large amounts of energy is needed to overcome and separate ions.

Question 11

Are ionic substances soluble? why?

Answer 11

• Most soluble in water
• Not soluble in organic solvents
  Water is attracted to the positive and negative ions and so will dissolve

Question 12

Are ionic substances good conductors ? why?

Answer 12

Can conduct when molten or in solution – has mobile ions.

Question 13

What allows a substance to conduct electricity ?

Answer 13

contain free moving charged particles. Charged particles cam be ions or electrons.

Question 14

Structure of simple molecular substances

what atoms, bonds

Answer 14

made up of a small number of non-metal aroms, held together by strong covalent bonds.

Question 15

bonds and force strength in simple molecualr substances

forces, bonds

Answer 15

covalent bonds between non metal atoms are very strong, forming individual molecules
held together by weak attractive forces

Question 16

Giant covalent substances structure

bonds, element types

Answer 16

networks made up of a large number of non-metal atoms, held together with a very large number of covalent bonds

Question 17

Bond and force strength of giant covalent substances

outlier

Answer 17

covalent bonds are very strong
Ony graphite has weak attractive forces

Question 18

What is an Allotrope?

Answer 18

two or more different physical forms of an element can exist

Question 19

What is the structure of diamond?

allotrope of what? bond, arrangement

Answer 19

allotrope of carbon.
Each atom is covalently bonded to 4 other carbon atoms in a tetrahedral arrangement

Question 20

properties and uses of diamond

strength, bonds, used in

Answer 20

very strong and hard because of the large number of strong covalent bonds which are hard to break
used in cutting tools

Question 21

What is the structure of graphite?

allotrope of , bonds, arrangement

Answer 21

allotrope of carbon
each atom is covalently bonded to 3 other carbon atoms ina hexagonal arrangement
each layer is a 2D giant molecule

Question 22

force strength of graphite

layers, electrons bond

Answer 22

between the layers are weak forces of attraction due to the remaining electron that is not bonded to any particular carbon atom.

Question 23

properties and uses of graphite

layers,

Answer 23

break easily, layers slide over eachother
used as a lubricant and in penicls

Question 24

is graphite a good conductor?

Answer 24

yes, due to delocalised electrons between layers

Question 25

structure of silicon oxide

bonds with what, arrangement,

Answer 25

formed when silicon atoms covalently bond to 4 oxygen atoms in a tetrahedral arrangement

Question 26

Properties of silicon oxide

similar, strength, mp.

Answer 26

simialr to diamond
hard with a high melting point