Covelant Bonds Flashcards
How many electrons does hydrogen have in its outer shell?
1
How many electrons does carbon have in its outer shell?
4
How many electrons does nitrogen have in its outer shell?
5
How many electrons does oxygen have in its outer shell?
6
How many electrons does chlorine have in its outer shell?
7
How any covenant bonds does hydrogen have?
1
How any covenant bonds does carbon have?
4
How any covenant bonds does nitrogen have?
3
How any covenant bonds does oxygen have?
2
How any covenant bonds does chlorine have?
1
What are ionic bonds always between?
A metal and a non metal
What are covenant bonds always between? What do they involve?
Two non metals, involves a shared pair of electrons
In a shared pair of electrons, where must the shared electrons be from?
One electron from each element
What are the properties of a simple covalent substance?
Low melting and boiling point, does not conduct electricity?
What are the properties of a giant molecular substance?
High melting and boiling point, does not conduct electricity, is not soluble
What is the one giant molecular substance that does conduct electricity?
Graphite
Why do simple molecular substances have low melting and boiling points?
Because weak molecular forces between molecules are broken easily
What are giant molecular structures held together by?
Strong covalent bonds
What holds atoms together?
Bonds
What holds molecules together?
Forces
Why can’t simple molecular substances conduct electricity?
Because everything is banded together and nothing is free to move.
How does the number of carbon atoms in a chain relate to melting and boiling points?
The more carbon atoms in the chain, the higher the melting and boiling points
What is a polymere?
A polymere is a large molecule containing chains of carbon atoms.
How are polymeres made?
They are made from joining together many smaller carbon chains
Why does melting boiling point increase with chain length?
Because as chain length increases there are more intermolecular forces between polymers, and energy is needed to break them
What are monomers?
Monomers are small, simple molecules that can be joined to make polymere
What are allotropes?
Allotropes are different structural forms of the same element
What are the four allotropes of carbon?
Diamond
Graphite
Graphing
Fullerenes
What are the two properties of allotropes of carbon?
They have high melting points due to large number of covenant bonds, and are giant covalent molecules
What is graphene? What are it’s notable properties?
It is an allotropes of carbon, 1 atom thick, giant covalent, exceptional strength, electrical conductor
What is fullerene? What are it’s notable properties?
It’s carbon covalently bonded to 3 carbons with a delocalised electron, spherical shape, low melting point, conducts electricity, poor reactivity, soft and slippery
Why is diamond hard?
Because the giant structure is held together by a strong tetrahedral arrangement of covalently bonded carbon atoms
Why is granite soft?
Because it is the only held together by weak intermolecular forces between the sheets of atoms
WHY do graphite and graphite conduct electricity?
Because delocalised electrons allow a flow of charge
Why is C{little 60} unstable as a SOlid st high temperatures?
Because there are only weak intermolecular forces between simple molecules
Why is graphene transparent?
Because it is made of a single 2D sheet of atoms
What are the results of delocalised electrons being free to move?
When a potential difference is applied, the electrons flow in one direction
Give five properties of metals
High density Usually solid at room temperature Shiny Conductor of heat and electricity Forms cations Sonorous - makes a ringing noise Iron, cobalt, nickel and copper conduct electricity High melting points Malleable - can be shaped Ductile - pull it and it becomes thinner Colourful
What is density?
Weight relative to volume
What is the one metal that isn’t solid at room temperature?
Mercury
What does it means for something to be sonorous
It makes a ringing noise
What 4 metals conduct electrocity?
Iron, cobalt, nickel, copper
What does it mean for something to be malleable?
It can be shaped
What does it mean for something to be ductile?
Pull it and it becomes thinner
What are four MAIN properties of non metals?
Low melting points
Poor conductor
Gas liquid or solid
Brittle
What are four MAIN properties of metals?
High melting point
Good conductors
Shiny solids
Malleable
What is the structure of metal?
Positive metal ions arranged in rows in | | | structure
| |
Held together by negatively charged delocalised electrons
What happens to the structure of metal when heated?
The positive ions will separate
What does it mean for an atom to be delocalised?
Not fixed in position/free to move around
Why is metallic bonding so strong?
Because the positive ions (cations) and electrons are strongly attracted to each other, so metallic bonding is strong and a lot of energy is needed to break bonds and change state
What happens when you apply force to metal?
The regularly arranged ions move over one another. Doesn’t break because ions are still held together by delocalised electrons
What’s an alloy? How does it compare to metal?
Metal and non metal or 2 metals nodded together. They are strong and less mailable than metal.
What are the properties of an ionic material? Give one example of one.
Conducts electricity when molten or dissolved. High melting and boiling points. Nacl(salt
What are the properties of an simple molecular material? Give two examples of one.
Low melting and boiling points
Weak intermolecular forces
Usually in gas or liquid states
H(little2)O , CO(little2)
What are the properties of an giant molecular material? Give two examples of one.
High melting and boiling points Doesn't conduct electricity Diamond, graphite Diamond doesn't Dissolve in water Graphite is the one giant molecular that does conduct electricity
What are the properties of an metallic material? Give two examples of one.
Conducts heat and electricity
Shiny, coloured
Medium melting and boiling points
Zinc, copper
