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.
What is the difference between a monomer and a polymer? (in terms of bonding)
A monomer has single bonds while polymers have multiple bonds.
What is the nucleus of the atom made up of?
Protons and neutrons
What do electrons do to a nucleus?
They orbit the nucleus in shells
What are the first six atoms that make up our universe?
Hydrogen Helium Lithium Beryllium Boron Carbon
How is the periodic table arranged?
In increasing atomic number
The do the rows on a periodic table tell us?
how many shells the atom has
What do the columns tell us in a periodic table?
The amount of atoms on the elements outer most shell
What is the atomic number?
The amount of protons
what is the mass number?
The amount of protons and neutrons
What are isotopes?
Elements are defined by the amount of protons, isotopes have the same number of protons but a different number of neutrons.
What are group one also known as?
The alkali metals
What are group zero also known as?
The noble gasses
What are group seven also known as?
The halogens
What is the law of conservation of mass?
atoms are neither created nor destroyed
What is the law of composition?
elements combine in fixed ratios
Who discovered the neutron?
Chadwick
Who discovered the electron?
J J Thompson
What was the Law of Octaves?
Atoms were arranged in atomic weight which was in some multiple of 8
Why was the law of octaves criticised?
Because some elements had no similar properties and were still placed in the same group. There was no clear division between metals and nonmetals.
What was Mendeleev’s version of the periodic table?
He placed atoms in increasing atomic weight, but put those of similar properties in the same groups. He also left gaps for undiscovered elements.
When were protons, neutrons and electrons discovered?
In the 20th century, the periodic table was updated.
Why are alkali metals stored under oil?
Because they are very dangerous and extremely reactive.
Why must you wear gloves when working with alkali metals?
Because they are highly corrosive, meaning that it can burn and eat away at living tissue.
What happens when alkali metals are exposed to air?
They tarnish quickly, going from shiny metals but react very quickly with air
Why do group 1 metals react more violently as you move down the group?
As there are more inner shells the outer shell gets further from the nucleus, this reduces the force of attraction, meaning it takes less energy to remove the outer shell
What happens when Alkali metals react with non-metals?
They react to form a white solid crystalline which dissolve in water to give a colorless solution
What type of bond does a group 7 element need to use when bonding to the same element and why?
A single covalent bond, this is because they have 7 electrons on their outer shell
What is chlorine used as in modern day society?
Chlorine is used to kill bacteria in the water supply
As you move down group 7, the reactivity decreases with it, why is this?
As you move down the atoms get bigger and there are more shells, this means that the attraction of the nucleus reduces. As you move down the ability to gain another electron decreases and so does the reactivity.
What happens to the oxidising power of the halogens as you move down the group?
The oxidising power decreases, this is because the electrons have to pull an electron into a shell further away from the nucleus, hence the atoms have a weaker pull
What happens to the reducing ability as to move down group 7?
Because there is a shell further away from the nucleus the ions have a weaker pull of the electrons hence losing the outer electron easier.
What happens when you react halogens with iron as you move up the group?
As you move up the group the reactions become more violent
What are the hazards of the halogens?
They are very oxidising agents and chlorine gas was used to kill British soldiers in WW1. Halogens are very dangerous and can be deadly if inhaled, ingested or absorbed into skin.
What happens to the boiling points of noble gasses (group 0) as you move down the group?
Their boiling points increase for the same reasons as halogens.
Why are noble gasses called group 0?
Because they have a full outer shell meaning 0 more electrons are needed.
What is an endothermic reaction and a exothermic reaction?
Endo- Bond breaking requires a lot of heat, this is called an endothermic reaction (heat is taken in)
Exo- Bond forming gives out heat energy and is known as an exothermic reaction
What happens during an exothermic reaction?
More energy is given out to the surroundings making the bonds than taken in to break the bonds.
What happens during an endothermic reaction?
Less energy is released making the bonds than taken from the surroundings to break the bonds, causing a decrease in temperature in the surroundings.
When are exothermic reactions used in real life?
They are used in power stations to generate electricity, to power cars, heat homes and to cook food.
How are exothermic reactions used in self heating cans?
Self heating cans have dual chambers, the outer chamber holds the food or drink and the inner chamber holds the chemicals which undergo a exothermic reaction, when the consumer wants to heat the contents the person pulls a ring which breaks the barrier of the chemicals and they react and undergo an exothermic reaction which releases heat.
When energy is being released (exothermic) is it a - or a +?
-
When energy is being taken from the surroundings (endothermic) is it a - or a +?
+
What does oxidation mean?
gaining or losing electrons
What is an ore?
A metal that has enough of one compound that its worth mining
What happens when metals react?
They lose their outer shell electron and become positive ions, the easier a metal loses its outer shell electron the more reactive it is.
What happens as you move down the reactivity series?
The more reactive a metal is because the further away it is from the nucleus because of the extra shells.
What happens when you move across a period?
The more you move across a period, the harder it is to lose an electron because you will have more electrons in the outer shell
What happens when acid reacts with metals?
the reaction produces hydrogen gas
What is displacement in reactions?
A more reactive metal will replace a less reactive metal from a compound.
What are two ways that metals are extracted from their ore?
Either by electrolysis or by reduction with carbon in a blast furnace
What are two ways that metals are extracted from their ore?
Either by electrolysis or by reduction with carbon in a blast furnace
What is OILRIG?
Oxidation is loss (of electrons) Reduction is gain (of electrons)
What charge is the cathode and anode and what moves towards it?
Cathode- negative charge
Anode- positive charge
They both attract oppositely charged ions.
What happens during electrolysis?
The compound is melted, when molten the ions are free to move. The ion that needs to lose electrons (oxidation) goes to the cathode and the ion that needs to gain electrons (reduction) goes to the anode.
What is an example of a half equation at the anode and cathode?
Cathode Mg+2 + 2e = Mg
Anode 2O-2 + 02 = 4e
What happens at the anode and at the cathode?
The negatively charged non metals are oxidised at the anode. The positively charged cations are reduced at the cathode to make metal atoms.
How is the reactivity of ions in electrolysis different in elements?
For example, metals are trying to lose their outer shell electron but metal IONS are trying to reduce (gain) electrons in electrolysis. If an element can lose an electron easily it will be harder for it to gain the electron back.
What is sodium chlorate used for?
To make bleach
What is sodium hydroxide used for?
To make soap and bleach
What does concentration mean?
The mass of a solute (chemical dissolved in water) in a given volume of solution.
What happens to the concentration when you increase the solute but keep the volume the same?
The concentration increases
What happens when you keep the solute the same and increase the volume?
The concentration decreases
What happens when we react a metal with oxygen?
A metal oxide is formed.
What is it called when you lose oxygen in a reaction?
reduction
What happens when metals react, what determines how reactive the metals are?
They lose the outer shell electron and form a positive ion. The ability to lose the outer shell electron and form a positive ion determines how reactive the metal is.
What does extraction of a less reactive element mean?
When a more reactive element displaces a less reactive element, e.g magnesium can displace iron oxide by taking the oxygen atoms
How is carbon used for the extraction of metals?
The carbon is very cheap therefore used, it is more reactive than, e.g iron and will displace it. The carbon will remove the oxygen atoms from the iron oxide to have the iron alone.
What’s the reactivity series in order?
Potassium sodium calcium magnesium zinc iron copper
