Topic 4 Flashcards
What do the properties of main group elements depend on?
Their s and p electrons
Which blocks of the periodic table are metals found?
S-block
P-block
Which groups of the periodic table are metals found?
1, 2, and 3
Which blocks of the periodic table are non-metals found?
P-block
Which groups are non-metals found?
Groups 4-8
What is the exception of Group 1?
Hydrogen
Why is Hydrogen an exception?
It is a non-metal, it reacts covalently and ionically
Why does Hydrogen attract electrons?
Because of its small size
What happens to Hydrogen when it reacts with metals?
It accepts electrons from the metal
What happens to Hydrogen when it reacts with non-metals?
It covalently shares electrons
How is H2 produced?
Methane reacts with steam to produce carbon monoxide and hydrogen gas
What is H2 used for?
Production of ammonia. hydrogenation of vegetable oils to make margarine, rocket fuel
What is the exception in group 2?
Be
What makes Beryllium different from other group 2 elements?
It has a small size and therefore higher electronegativity so it forms covalent bonds with covalent character?
What is the characteristics of Beo?
It is covalent and amphoteric
Why doesn’t BeCl2 not have a full octet?
Because the type of bond it creates
What kind of bond does BeCl2 create
Dative bonds and Bridge bonds
What is a Dative bond?
Bonds that occur when 2 atoms make a bond but both electrons come from one atom only
What is a Bridge Bond?
A bond with 3 atoms and 4 electrons
How does BeCl2 form a Bridge bond?
The Cl shares two electrons pairs with two Be’s
What kind of structure does BeCl2 form?
A polymeric structure
What kind of bond does BeH2 form?
A banana bond
What is a Banana bond?
A 3 center 2 electron bond
How does Be form a Banana bond in H2?
The H shares its electrons with 2 Be each
What is the exception in Group 3?
Boron
Why is Boron the exception of group 3?
It is a semimetal
What is the exception in Group 4?
Carbon
What are the 3 reasons that Carbon is an exception?
1) Carbon Carbon single bonds are more common the Si-Si bonds
2) Carbon can form double and triple bonds
3) Carbon forms strong oxides
Why are Carbon Carbon bonds stronger than Si-Si?
They are more stable which is shown through the high amount of energy required to break them
Why can’t silicone form multiple bonds?
It is too large
Why are Carbon Oxides stronger than Silicone Oxides?
Carbon oxides can form pi bonds which are strong bonds
What kind of structures do Carbon oxides form?
Molecules
What kind of structures do Silicone Oxides form?
Extended structures
What is the exception in group 5?
Nitrogen
What makes nitrogen the exception?
It can form pi bonds
Why can nitrogen form pi bonds?
Because its smaller
What is the exception in Group 6?
Ocygen
Why is oxygen the exception?
It is small so it can form pi bonds
What is Metallurgy?
The science of production and purification of metals
How does Extraction by Reduction of a metal work?
Carbon or hydrogen is used along with heat to reduce the metala
How does Extraction by Electrolysis (of a molten compound) work?
A molten ionic compound is heated heated so that it separates into its ions. An electric current is then ran through it to create the atoms
Why is Boron an exception?
It is a semi-metal, forms covalent bonds
What are hydrides of Boron known as?
Boranes
What is the stability of BH3?
It is very unstable because it is poor in electrons
What does BH3 undergo?
Dimerization to form B2H6
What kind of bonds does B2H6 have?
3 center 2e banana bonds with terminal bonds being regular covalent bonds
What are the characteristics of Aluminium?
- Most abundant metal in the earth’s crust
- High thermal and electrical conductivity
- Forms covalent bonds with non-metals
How does Al in AlCl3 complete its octet?
It undergoes dimerization with Cl sharing it electrons with aluminium with dative bonds to form Al2Cl6
What are the characteristics of Gallium?
It exists as a liquid over a wide range of temperatures
What are the Properties of Indium?
Same as aluminium and Gallium. Has multiple oxidation states of +1 and +3
What are the Properties of Thallium?
Has more chemical properties of a metal
Both +1 and +3 oxidation states
What does it mean on a Phase Graph if the line that separates solids and liquids bends to the right?
The solid phase is more dense than the liquid phase
What does it mean on a Phase Graph is the line that separates solids and liquids bend left?
Solid phase is less dense than the liquid phase
What are the 3 Allotropes of Carbon?
Graphite
Diamond
Fullerenes
What is the atomic Structure of Graphite?
Central carbon bonded to 3 other carbons one with a double bond. It also has a hexagonal structure
What is the Conductivity of Graphite?
Can conduct electricity because of the free electrons in the pi bond
What are the layers of Graphite held together by?
Van der Waals forces that slide past each other easily
Why does Graphite have a high melting point?
Because the bonds between carbon atoms are strong but the forces between the layers are weak
What type of structure does Diamond have?
A 3 dimensional tetrahedral structure
What is the atomic structure in Diamonds?
Central carbon bonded to 4 other carbons with single bonds
What kind of melting point that does diamond have?
A high one
What is the Conductivity of diamonds?
Does not conduct electricity but good conductor of heat
What are Fullerenes?
Molecules of Carbon with hollow shapes
What are examples of Fullerenes?
Carbon Nanotubes, buckyballs C60, hexagonal shapes for both
What are the Allotropes of Silicone?
Silica and Silicates
What is Silica?
SiO2
What is Silicates?
SiO2 combines with other elements
What do Ge, Sn, Pb exist as?
In the forms of sulfides and oxides
What kind of bonds do all group 4 elements create?
4 Covalent bonds with non-metals forming tetrahedral molecules with sp3 hybridization
What are the properties of Silicon and Germanium?
- Semi-metals
- Semiconductors in electronics
What are the properties of Sn?
Soft and silvery white metals
What are the components of bronze?
88% copper 12%tin
What are the components of Solder?
11% tin 37% lead 42% Bismuth 10% Cadmium
What are the components of Pewter?
85% tin 15% (Cu, Bi as hardeners)
What are the 3 Allotropes of Tin?
Grey (Alpha)
White (Beta)
Gamma
What are the properties of Grey (Alpha) tin?
Most stable form, transforms into white above 13.2 degrees
What are the properties of White (Beta) tin?
Commonly found form of Sn (Normal) tin
What are the properties of Gamma tin?
Exists at very high temperatures
What are the Non-metals in group 5?
Nitrogen and Phosphorus
What is the semimetal in group 5?
Arsenic
What are the metals in group 5?
Antimony
Bismuth
Why do heavier elements tend to have more metallic properties?
Because their size increases so their electrons have less attraction to the core which means they can lose electrons more easily
Why is Phosphorus different than Nitrogen?
Nitrogen is more easily able to make pi bonds because of its small size. Phosphorus can use its d-orbital and nitrogen cannot. Nitrogen is less electronegative
What are the 3 allotropes of Phosphorus?
White
Black
Red
What are the properties of White Phosphorus?
Very Reactive
Can ignite itself
Tetrahedral
What are the properties of Black Phosphorus?
Crystal array
Conducts electricity with lone pairs
Most stable form of phosphorus
What are the properties of Red Phosphorus?
Chainlike Polymeric
How is Red P made?
White and heat at 1 atm
How is Black P made?
White or Red P and heat and 12000 atm