Chemistry ovr Flashcards
What is the Definition Of Atomic Number
The atomic number represents the number of protons and indirectly shows the number of electrons (atoms are stable)
What is the Relative Atomic Mass
The Relative Atomic Mass represents the number of subatomic particles in the nucleus + electrons
What are the three subatomic particles
Protons, Neutrons and Electrons
Charge and Mass of Proton
Mass=1
The charge is positively charged
Charge and Mass of Neutron
Mass=1
The charge is neutral
Charge and Mass Of Electron
Mass= 1/1836
The Charge is negative
Charge of an Atom and Why?
No overall Charge because of Num Of Protons= Num of Electrons
How to Calculate RAM
Num of Protons + Num of Neutrons
How to calculate Num of Protons
Same as the Atomic Number
How to calculate the Num of Electrons
Same as the Atomic Number
How to Calculate the Num of Neutrons
RAM - ATOMIC NUMBER
Because RAM = protons and neutrons
ATOMIC NUMBER = protons
What is the Group Number?
Represents the Num of electrons in the outer shell
What is the Period Number?
Represents the Num of electron shells surrounding the nucleus
What is Ionic Bonding
Ionic Bonding is the electrostatic force of attraction between positively charged ions and negatively charged ions. (Metals and Non Metals)
What does the Compound of Ionic Bonding lead to?
Formation of Salts
What does it mean by the electrostatic force of attraction?
When 2 oppositley charged ions attract
Why do elements undergo Ionic Bonding?
This is because all elements want to acheive a full outershell.
How does it Ionic Bonding occur?
When a non metal combines with a metal the non metal has a stronger attraction for electrons than the metal so metals are transffered from the outer shell.
Why Are Non Metals Negatively Charged?
Because an Electron has a negative charge and when something gains an electron it will become negatively charged as there are more electrons than protons.
Why are Metals Positively Charged
Because an Electron has a negative charge and when it loses an Electron it will have more protons then electrons making it positively charged.
What is Covalent Bonding
When Electrons are shared between 2 non-metal atoms to acheive a full outershell.
What is Metallic Bonding
The Electrostatic Attraction between the sea of delocalised electrons and the positively charged metal atoms.
Properties Of Ionic Bonding in terms of electrostatic attraction
Very Strong Electrostatic Attraction
Properties of Ionic Bonding in terms of melting and boiling point
Ionic Compunds have a high melting and boiling points because the electrostatic force of attraction between the positive metal ions and the negative non metal ions is so strong that it requires a lot of energy to break therefore having a high melting and boiling point
Properties of Ionic Compounds in terms of Conductivity
Can Conduct when molten or when dissolved in water. This is because free movement of ions can lead to the generation of a current
Properties Of Ionic Compounds in terms of arrangement
Ionic Compounds generate a lattice arrangement. This is because oppositely charged ions, attract in all directions
What are the 2 main groups of covalent structures
Simple Molecular e.g. H20, CO2
Giant Covalent e.g. Diamond, Graphite, Fullerene
Is the melting/boiling point of simple molecular structures high or low?
Low Melting and Boiling points as small amounts of energy are needed to overcome the weak intermolecular
forces that exist between adjacent compounds
Properties Of Simple Molecular Structure in terms of conductivity?
In general simple molecular compound, e.g. CO2 does not conduct electricity
What types Of Giant Covalent Network structures are there
Diamond, Graphite and Fullerene
What are Diamond, Graphite and Fullerene made from
Carbon atoms only
Explain the structure of a diamond in a Giant Covalent Network
Each carbon atoms forms a covalent bond with 4 oher carbon atoms. this generates a giant network of carbon atoms
Properties of Diamond in terms of Melting Point
The Melting and Boiling Point of Diamond is high because high amounts of energy is needed to overcome the weak intermolecular forces that exist between adjacent compounds
Properties of Diamond in terms of Toughness
Diamond is Tough because the covalent bonds are very strong
Properties of Diamond in terms of conductivity
Diamond does not conduct electricity as it does not have any available delocalised electrons to conduct a current
Explain the structure of Graphite in Covalent Bonding
Each Carbon atom forms a covalent bond with 3 other carbon atoms. because of this it will have free electrons that will become delocalised
Properties of Graphite in terms of conductivity
Can conduct electricity as the delocalised electrons are free to move in between the layers/ sheets of carbon atoms
Explain the structure of Fullerene
Molecular Structure - C60, forms a hollowsphere
Properties of Fullerene in terms of Conductivity
Fullerene does not Conduct electricty because it has no free delocalise electrons.
Properties of Fullerene in terms of Melting and Boiling points
High melting and Boiling points as the c-c bonds are strong and as it forms a giant covalent network.
Properties of Metals in terms of conductivity
Can conduct electricity since they have free delocalised electrons that can move to generate a current. They can also conduct heat
Properties of Metals in terms of malleability and ductility
Metals are malleable and ductile as they have layers of positive metal ions that can slide over each other
Properties Of Metals in terms of Melting and Boiling point
Metals have a high melting and boiling point because the electrostatic force of attraction between the positively charged metal ions and the sea of delocalised electrons is
so strong that a lot of energy is required to break this bond therefore having a high melting and boiling point
How does Metallic Bonding occur
Electrons become delocalised from metal atom generating metal ions due to imbalance of electrons and protons within the metal ion
Definition Of Metallic Bonding
Metallic Bonding refers to the electrostatic attraction between the sea of negatively charged delocalised electrons and the positively charged metal ions.
Definition Of Isotopes
Atoms of the same element (herefore they have the same number of protons) but they have a different relative atomic mass (therefore they have a different number of neutrons
What is the Definiton of an Element
only one type of atom
What is the definiton of a Compound
2 or more different types of atoms chemically bonded together
What is the Definition of A Mixture
2 or more different types of atoms not chemically bonded together
What is Filtration
Filtration is the seperation of an insoluble solid from a liquid
What is Crystillisation
Crystillisation is the seperation of an soluble solid from a liquid
What is Chromatography
Chromotography is the seperation of mixtures you can identify the mixtures by determining its Rf value.
How do you calculate the Rf value
Distance travelled by solute/Distance travelled by solvent
What is Distillation
Distillation is the seperation of liquids based upon the different boiling points
What is Crude Oil made up of
Crude Oil is a mixture of different hydrocarbons of different chainlengths
Why do all Group 1 elements react in the same way
This is because they have one electron in the outer shell
What is the order of reactivity in Group 1
As you descend in Group 1 reactivity increases this is because the size of the atom increases and therefore the number of electron shells surrounding the positively charged nucleus increases protecting the electrostatic attraction between the positively charged nucleus the negatively charged outer electron. This makes it easier for the outer electron to be transferred in reactions
One way to identify the order of reactivity is by (Group 1)
Alkali metal + Water -> Metal Hydroxide + Hydrogen
Hydrogen -> Squeaky Pop test
To carry out this test use a lighted splint and place it above the chamber in which the reaction has taken place
What are Group 7 elements regarded as
Halogens
What is the state of Cl at room temp
Cl is a green reactive and poisonous gas
What is the state of Bromine at room temp
Br is a poisonous red-brown liquid that produces orange vapour
What is the state of Iodine at room temp
forms a dark grey crystalline solid that produces purple vapour
What is the trend in the Boiling Point in the group (Group 7)
Boiling Point increases as you go down the group. This is because the size of the atom increases
What is the trend of reactivity in group 7
As you descend down the group reactivity decreases, this is because the size of the atom increaaes and the amount of electron shells protecting the electrostatic attraction between the positively charged nucleus and the negative charged external electron increases. This makes it much more difficult for the halogen to attract an electron and therefore react in a chemical reaction
What is a Displacement Reaction
A displacement reaction is where a more reactive element pushes out a less reactive element from a compound
What are the three states of matter
Solid Liquid Gas
Describe the arrangement of a Solid
Packed, Strong and regular arrangement
Vibrating around its own position
Connected to each other by strong molecular bonds
Describe the arrangement of a Liquid
Less regular arrangement
Particles have slightly greater kinetic energy compared to particles at solid state
Describe the arrangement of A Gas
Have large amounts of Kinetic Energy
Move in all random directions
What are Isotopes?
Atoms of the same element that have a different number of neutrons
(Same atomic number but different RAM)
What is the trend of Group 7 halogens in the group? In terms of Boiling Point?
Boiling Points of the halogens increase as you descend down the group. We know this as Fluorine and Chlorine are gases at room temperature, bromium is liquid at room temperature and iodine and astatatine are both solids at room temperature.
What is the trend of Group 7 halogens in the group in terms of reactivity?
The order of reactivity descends as you go down the group because the size of the atom increases. Therefore the number of shells protecting the electrostatic attraction between the positively charged nucleus and the negatively charged external electrons decreases. This makes it much more difficult for the halogen to accept the external electron and therefore to participate in a chemical reaction.
If you start with Potassium Chloride (Kcl (aq) colourless)
and add Cl2 water what will you observe
No reaction
If you start with Potassium Chloride (Kcl (aq) colourless) and add Br2 water, what will you observe?
No reaction
If you start with Potassium Chloride (Kcl (aq) colourless) and add I2 water, what will you observe)
No reaction
If you start with Potassium Bromide (KBr (aq) colourless) and add Cl2 water what will you observe?
Orange Solution (Br2)
If you start with KBr aq colourless and add Br2 water, what will you observe?
No reaction
If you start with KBr aq colourless and I2 water, what will you observe?
No reaction
If you start with KI (aq) and add Cl2 water, what will you observe?
Brown
If you start with KI and add Br2 water, what will you observe?
Brown
If you start with KI and add I2 water, what will you observ?
No reaction
What is a redox Reaction?
A redox reaction is where a substance in a chemical reaction is reduced or oxidised
What happens to a substance if it is Oxidised and Reduced?
Oxidiation- Loss of Electrons and gains O2
Reduction-Gains Electrons and loses O2
What is an Oxidising agent?
A substance that has the abillity to oxidise other substances.
What is a Reducing agent?
A substance that has the abillity to reduce other substances
How much Nitrogen is in the atmosphere? (%)
78
How much Oxyen is in the atmosphere? (%)
21
How much Argon is in the atmosphere? (%)
1
How much Carbon Dioxide is in the atmosphere? (%)
0.04
What happens to Magnesium when Burnt?
Produces Magnesium Oxide which forms a white powder