Paper 1 Flashcards
What are all atoms goals?
To get a full outer shell
What does it mean when an element has a +1 charge or a -1 charge.
It is the amount of protons in comparison to electrons, e.g 11 protons and 10 electrons = +1 charge.
Explain how magnesium bonds to oxygen to form magnesium oxide?
oxygen has a configuration of 2,8,6 and magnesium has a configuration of 2,8,2. Magnesium will transfer 2 outer shell electrons to oxygen leaving them both will full outer shells. Magnesium will have a +2 charge and oxygen will have a -2 charge.
What happens when there is an ionic bond between a nonmetal and a metal?
Metals form positive ions and nonmetals form negative ions. An ionic structure is then formed between the strong electrostatic attractions between the positively charged ions, making a giant ionic structure.
What is covalent bonding?
A pair of negatively charged electrons which are held by the electrostatic force between the positively charged nucleus and the two atoms.
Why is carbon able to make giant covalent structures such as diamond, graphite and silicon dioxide?
This is because carbon has 4 electrons in its outer shell, meaning it can bond to itself almost infinitely.
What are alkenes and what does it undergo? What is this called?
Hydrocarbons with double bonds that can undergo a unique chemical reaction called polymerisation , this is where lots of small molecules can join together to make a big molecule called a polymer.
What are molecules of alkenes referred to as?
Monomers
What is the bonding like in the outer shell of a metal?
The outer shell electrons of a metal are not strongly held together by the nucleus hence they are donated to a sea of delocalised electrons which move about a lattice of positive ions. The bonding arises because of the strong electrostatic forces between the electrons and the lattice of positive ions
What are the three states of matter? How are they arranged?
Solid- regular arrangement, vibrate around a fixed position and they are very close
Liquid- randomly arranged, close and move around each other
Gas- randomly arranged, move quickly in all directions, far apart
What is a melting and boiling point?
Melting point- the point where a solid becomes a liquid
Boiling point- the point where a liquid becomes a gas
What is a freezing and condensing point?
Freezing point- when a liquid becomes a solid
Condensing point- when a gas becomes a liquid
Why do ionic compounds have high melting and boiling points?
Because of the many strong electrostatic forces between the negatively charged ions and a lot of heat is required to overcome these bonds hence the high melting and boiling points
When are ionic compounds able to conduct electricity and why?
They are able to conduct electricity when they are molten or in a solution, this is because the ions are free to move so charge can flow.
Why are ionic compounds brittle?
This is because each positive ion is surrounded by a negative ion and vice versa. When they are hit the charged ions will line up, the charges then repel each other causing it to fall apart.
Why do simple covalent substances have low melting and boiling points?
Simple covalent substances consist of a small number of atoms covalently bonded together. They have weak intermolecular forces that do not require a lot of heat to overcome, hence having a low melting and boiling point.
what happens to the melting and boiling point as simple covalent molecules get bigger?
When they get bigger there are more attractions between each molecule hence the melting point increases.
Why does graphite conduct electricity?
This is because each carbon atom is bonded to 3 other carbon atoms leaving one atom to make up a delocalised sea of electrons that can carry charge between the layers.
Why do simple covalent bonds and giant covalent bonds (apart from graphite) not conduct electricity?
They are uncharged and have no free electrons to carry the charge.
Why is graphite soft and slippery?
This is because each carbon atom is bonded with three other carbon atoms arranged in layers. The layers can easily slide over each other because the forces between the layers are weak (not covalent) so are easily broken
Why does diamond have a high melting point and why does it not conduct electricity?
Each carbon atom is bonded to 4 other carbon atoms meaning there is no free electron to conduct electricity and it takes a lot of heat to overcome the strong and multiple bonds.
Why does graphite have a high melting point?
because each carbon atom is bonded to three other carbon atoms in a giant covalent structure, meaning a lot of heat is needed to overcome this.
Why does silicon dioxide (sand) have a high melting point?
This is because every silicon atom is covalently bonded to four oxygen atoms in a giant covalent structure, it requires a of heat to overcome these bonds because there are many and they are strong.
Why does silicon dioxide NOT conduct electricity?
Each silicon atom is covalently bonded to four oxygen atoms levaning no electron free to carry charge
Why is sand hard?
Sand is hard because the strength of the covalent bonds give it a strong and rigid structure.
Why does graphene conduct electricity?
Graphene is one layer of graphite and conducts electricity for the same reason as graphite.
How many carbon atoms does buckminsterfullerene contain?
60 atoms
How is buckminsterfullerene structured?
Each carbon atom is bonded to three other carbon atoms one single bond and two double bonds. These atoms are arranged in 12 pentagons and 20 hexagons creating a spherical shape.
Why is buckminsterfullerene a good lubricant?
Buckminsterfullerene has molecules which are spherical meaning the molecules will roll.
What are positive ions called?
Cations
Why do metals conduct electricity?
Metals conduct electricity because the outer shell electron is not held together well by the nucleus, hence metals have a sea of delocalised electrons which move about a lattice of positive ions. The sea of
Why do metals have a high melting point?
They have a high melting point because the ions and the sea of delocalised electrons have a strong attraction meaning a lot of heat is required to overcome this attraction.
What is an alloy and why is it used?
An alloy is made up of two or more metals because the layers in metal will be harder to slide when force is applied.
What is the bonding and structure like in metallic substances?
The atoms are all the same size and are arranged in layers, if a big enough force is applied to overcome the attraction between the atoms then one layer of atoms will slide past the other.
What is a smart alloy?
A smart alloy is a metal that remembers its original shape,when it is deformed it will remain at that shape but when it is heated to a certain temperature then it returns to its original shape.
What are disadvantages of smart alloys?
Their high cost and metal fatigue, which is when deforming the metal leads to it breaking.
What are the two ways polythene can be made?
One way leads to chains with branches and the other leads to straight and ordered chains that line up like the atoms in a crystal.
Which version of polyethene is more dense and has a higher melting point?
The ordered and straight rows of atoms are stronger, more dense and have a higher melting point.
What is a polymer molecule?
A long chain of carbon atoms that are held together by strong covalent bonds.
Why does giant ionic structures have a high melting and boiling point?
This is because the strong electrostatic forces between the positive and negative ions are hard to overcome (requires lots of energy to break them)
Why can’t ionic compounds conduct electricity?
because they are locked in place by the strong electrostatic forces.
Why can ionic compounds conduct electricity once they are melted?
because the ions are no longer locked in place and are now free to move.
What element have covalent bonds?
non metals
Why do small covalent molecules have low melting and boiling points?
As temperature increases the weak intermolecular forces break at a very low temperature because little energy is needed to overcome the intermolecular forces. The molecules then boil and change state.