Structure and Bonding 1.37-1.60C Flashcards
What is an ion and how are they formed?
Charged particle
Formed by gain or loss of electrons which dictates the charge of an ion
What is a cation and how is it formed?
Positive ions - lose electrons
What is an anion and how is formed?
Negative ion - gain electrons
How do groups 1,2 and 3 (metals) form ions?
Lose electrons to form positive ions
Group 1 = 1+
Group 2 = 2+
Group 3 = 3+
How do groups 5,6, and 7 (non-metals) form ions?
Gain electrons to form negative ions
Group 5 = 3-
Group 6 = 2-
Group 7 = 1-
What is the charge of Ag?
+
What is the charge of Cu?
2+
What is the charge of Fe (II)?
2+
What is the charge of Fe (III)
3+
What is the charge of Pb?
2+
What is the charge of Zn?
2+
What is the charge and formula of hydrogen?
H+
What is the charge and formula of hydroxide?
OH-
What is the charge and formula of ammonium?
NH4+
What is the charge and formula of carbonate?
CO3^2-
What is the charge and formula of nitrate?
NO3^-
What is the charge and formula of sulfate?
SO4^2-
What happens when a metal reacts with a non-metal?
Ionic compound
Metal loses electrons = Positive ion
Non-metal gains electrons = Negative ion
These ions are strongly attracted to one another by electrostatic attractions - ionic bond
Define ionic bond
The strong electrostatic force of attraction between positive and negative ions
How are ionic compounds represented?
Dot and cross diagrams
What structure do ionic compounds have?
Giant ionic lattice
Why do ionic compounds have high melting and boiling points?
Structure - they have a giant ionic lattice structure
Bonding - Held together by the strong electrostatic force of attraction between positive and negative ions
Energy - a large amount of energy is required to break the attraction to melt the substance
Can ionic compounds conduct electricity and why?
Can in solution and molten NOT solid
Solid - ions are fixed in the lattice (no charged particles can move)
Molten and solution - ions no longer fixed and free to move
What are the conditions for electricity?
Charged particles that can move
What types of element is covalent bonding between?
Non-metal and non-metal
Define covalent bonding
The strong electrostatic force of attraction between the negatively charged shared pair of electrons and the positive nuclei of both atoms in the bond
ON PAPER draw the dot and cross diagrams of:
hydrogen, chlorine, hydrogen chloride, ammonia, nitrogen, oxygen, water, methane, carbon dioxide, chloromethane, ethane, ethene
What is a simple molecules substance?
Substance made up of molecules (which are joined together by covalent bonds) - weak intermolecular forces of attraction between molecules
Why do simple molecular structures have low melting/boiling points?
Structure - simple molecular structure
Bonding - weak intermolecular forces of attraction
Energy - not much energy is required to break the weak intermolecular forces of attractions between molecules
Why do melting and boiling increase as molecular mass increase? (simple molecular substances)
Intermolecular forces of attraction become stronger as relative molecular mass increases so more energy is needed to break the attraction = higher boiling point
Can simple molecular substances conduct electricity?
No because the molecules don’t have any overall electrical charge (no ions) and all electrons are held tight in atoms or in covalent bonds so cannot move from molecule to molecule
Why do giant covalent structures have high melting and boiling points?
Structure - giant covalent lattice structure
Bonding - held together by strong covalent bonds
Energy - therefore a large amount of energy is required to break the bonds
Why is diamond very hard?
Made up of carbon atoms in a rigid tetrahedral lattice that each form 4 covalent bonds
Why can diamond and giant covalent structures not conduct electricity?
Electrons are localised in covalent bonds
Atoms are localised
Therefore no charge particles can move
How does the structure of graphite differ from other giant covalent structures?
- Each carbon atom only forms three covalent bond so they are arranged in layers of hexagons
- Weak forces of attraction between layers
Does graphite have a high or low melting point and why?
High
- Giant covalent lattice structure with strong covalent bonds
- Need lots of energy to overcome the forces of attraction
What is a characteristic of graphite as a material and explain why this is
Soft material
Weak forces of attraction between the layers so slide over each other easily
Does graphite conduct electricity and why?
Yes
Only 3 out of each carbon’s four outer shell electrons are used in bonds so each carbon has one delocalised electron which is free to move
Does C60 fullerene have a low or high melting/boiling point and why?
Structure - simple molecular structure
Bonding - weak intermolecular forces of attraction between molecules
Energy - not a lot of energy required to overcome the forces of attraction
Why is C60 soft and slippery?
Weak intermolecular forces of attraction so molecules slide over each other easily
Can C60 fullerene conduct electricity? Explain why
Electrons are localised on each molecules
Molecule is neutral overall
Therefore no charged particles can move
Define metallic bonding
The strong electrostatic force of attraction between the positive ions and delocalised electrons
Do metallic bonded substances have high or low melting/boiling points?
High
Structure - Giant metallic lattice
Bonding - strong electrostatic forces of attraction between positive ions and delocalised electron
Energy - large amount of energy needed to break bonds
Do metals conduct electricity and heat?
Yes
Sea of delocalised electrons which can move
Movement of electrons means energy can be transferred quickly through the material, so metals are good conductors of heat
Describe the structure of metallic bonding
Sea of delocalised electrons
Giant lattice of positive ions
What does malleable mean?
Can be hammered or rolled into flat sheets
Why are metals malleable?
The atoms are arranged in layers
Easy for the layers of atoms to slide over each other
What is an alloy?
A mixture of two or more metals
