Flashcards in Structure and Bonding Deck (60):
What is the atomic number?
The number of protons in an element. The small number.
What is the mass number?
The number of protons plus neutrons in an element. The big number.
Wha is an isotope?
Different atomic forms of the same element that have the same number of protons, but a different number of neutrons.
What is relative atomic mass?
how heavy an atom is compared to a carbon-12 atom.
How to calculate relative atomic mass?
Take the relative mass of every isotope, and multiply it by the number of isotopes there are, and add them, then divide it by the number of isotoped added.
What do the columns in the periodic table represent and how are they called?
they are called groups and they represent how many electrons are in the last outer shell.
What do the rows in the periodic table represent and how are they called?
They are called periods and represent how many shells it has.
What are group 1 elements called?
What are group 7 elements called?
What are group 0 elements called?
Why do elements in the sane group of a periodic table have similar chemical properties?
because they have the same amount of electrons in their outer shell.
Why do noble gases have a lack or reactivity?
Their outer shell is full.
Define metallic bonding.
A pool of metal positive ions surrounded by a sea of delocalised electrons. A bond between two metal ions.
What is an ion?
An atom that has a positive or negative charge. This happens when an atom loses or gains electrons.
What is oxidation?
The loss of electrons or addition of oxygen.
What is Reduction?
The gain of electrons or removal of oxygen.
What is ionic bonding?
It is bonding between a metal and a non-metal atom trough the attraction between two ions of opposite charges.
Why do ionic compounds have high melting and boiling points?
Because the strong ELECTROSTATIC force between oppositely charged ions is hard to break. Therefore requires a lot of energy.
What is a covalent bond?
A bond between two non-metals that share a pair(s) of electrons between two atoms.
Why do covalent bond substances have a low melting and boiling point?
Because the to melt or boil a substance, you only need to separate the molecules from each other, so the bond between the atoms doesn't have to be broken, and the intermolecular bond is weak, so it doesn't require much energy to break, therefore doesn't require much heat to break.
What are the gases in air plus %?
Oxygen 20%, Nitrogen 78%, Argon 1%, CO2 0.04%, H2o vapour, depends.
What are the gases that contribute to acid rain?
Sulfur dioxide and nitrogen oxides.
What are the problems caused by acid rain and what is it?
ph of rain below 5.6, causes the lakes and rivers to be acidic, which is dangerous for the animals.
What is crude oil?
A mixture of hydrocarbons.
What does fractional distillation do?
It separates crude oil into fractions.
What are the 7 fraction in distillation? (from low heat to high)
Bitumen, Fuel Oil, Diesel, Kerosene, Naphtha, Gasoline, Refinery gases.
What is Bitumen used for?
What is Fuel Oil used for?
Fuel for ships, heating
What is Diesel used for?
Fuel for diesel engines
What is Kerosene used for?
Jet engines, paint solvent
What is Naphtha used for?
What is Gasoline used for?
What is Refinery Gases used for?
Bottled gas, heating.
What is a Homologous Series?
A series of compounds that have similar properties and the same general formula.
What is a hydrocarbon?
A compound which is made from carbon and hydrogen atoms only. One family of hydrocarbons is the alkanes.
What does saturated mean?
That the atoms are bonded with a single covalent bond
What does unsaturated mean?
Not all bond are single bonds.
A formula followed by each member of a homologous series.
What is an isomer
The atoms in a compound are arranged differently.
What is the general formula for alkanes
When does incomplete combustion of alkanes occur?
When there isn't enough oxygen
What are the products of complete combustion of alkanes?
Carbon dioxide + Water (+energy)
What are the products of incomplete combustion of alkanes?
Carbon + Carbon Dioxide + water
What is the general formula for Alkenes?
Why doesn't an alkane react with bromine water?
because it's saturated
How is an addition polymer made?
By joining up a lot of smaller molecules monomers.
Why are the issues of Polymers?
They don't biodegrade easily so they are hard to dispose of.
What does redox mean?
A type of reaction involving reduction and oxidation.
reducing agent transfers electrons to another substance - and so reduces it
an Oxidising agent gains electrons from another substance - and so Oxidises it
What does the method of extraction of Aluminium tell us about its position in the reactivity series?
That it is above carbon since it needs electrolysis
What does the method of extraction of Iron tell us about its position in the reactivity series?
That it is below carbon since it needs Heating with carbon monoxide.
why does an ionic substance need to be molten or aqueous in order to conduct electricity?
Because the electrons need to be free to move.
Describe the extraction of aluminum in detail. (3)
It is dissolved in cryolite to decrease the melting point (therefore the cost), the positive electrodes need to be replaced because it gets worn down by reacting with oxygen, and the cost of electricity for the reaction is a major factor.
Ionic half-equation for reaction at the electrodes in aluminum extraction.
At negative electrode(cathode) : Al3+ + 3e- → Al
At positive electrode (anode) : 2O2- → O2 + 4e-
What is the color of halogens and physical state at room temperature?
Chloride (green, gas), Bromine (red-brown, liquid), Iodine (dark-grey, solid)
What do halogens displace?
a more reactive halogen can displace a less reactive halogen.
What are the colors of the universal indicator?
blue is alkaline, green is neutral, red is acidic.
On the ph scale, what is acidic and alkaline?
0 is acidic, 14 is alkaline