Atoms, bonding and moles Flashcards
What is an Element?
An element is a substance that only contains on type of atom.
What is the mass number of lithium?
[https://sciencenotes.org/hd-wallpaper-periodic-table/]
7
What is the Atomic number for Lithium?
[https://sciencenotes.org/hd-wallpaper-periodic-table/]
3
What is the mass number for Aluminium?
[https://sciencenotes.org/hd-wallpaper-periodic-table/]
27
What is the atomic number for Aluminium?
[https://sciencenotes.org/hd-wallpaper-periodic-table/]
13
What is the atomic mass equal to?
The number of protons
What is the mass number equal to?
The number of protons + neutrons
What is the number of protons equal to?
The number of electrons
How do you find out the number of electrons?
Its the same as the number of protons or the atomic number
How do you find the number of neutrons?
You do atomic number take away mass number
What is an isotope?
Isotopes are atoms of the same element that have the same number of protons but a different number of neutrons, and therefore different mass numbers.
How do you calculate the relative atomic mass for an isotope?
You have to do:
(mass of isotope 1 X % of isotope 1) + (mass of isotope 2 x % of isotope)
/100
If (10)B has an isotopic abundance of 20% and (11)B has a n isotopic abundance of 80%, calculate the relative atomic mass:
You do (10 X 20) + (11 X 80) = 1080/100 = 10.8
/(20+80)What is a compound?
Compounds are formed from elements in chemical reactions. A chemical change happens and at least one new product is formed. Elements are combined in fixed proportions and compounds can only be seperated by chemical means.
What is a mixture?
Mixtures are formed from elements or compounds combined by non-chemical means. The elements/compounds are unchanged, the elements/compounds in mixtures can be combined in any proportions and mixtures can be separated by physical means
What is this method of mixture separation called and what is its purpose?
[https://theartofseparationtechniques.blogspot.com/2010/08/filtration.html]
It is filtration and it is used to separate an insoluble solid (residue) from a liquid (filtrate).
An example of this could be separating sand from water.
What is this method of mixture separation called and what is its purpose?
[https://www.toppr.com/ask/content/concept/crystallization-and-fractional-crystallization-244871/]
It is crystallization and it is used to sperate a soluble solid from a solvent.
For example, copper sulfate crystals from water.
How does Chromatography work and what is its purpose?
A drop of mixture is placed on chromatography paper, which is placed in a solvent (usually water). Over time, the solvent soaks up the paper and the different substances in the mixture move at different speeds depending on how strongly they interact with the paper, causing them to separate.
Used to separate multiple soluble substances like inks
How does Distillation work and what is its purpose?
The mixture is heated and the solvent boils. The vapour passes through the condenser, cools and condenses as a liquid in a collection vessel. The solute is left in the original flask.
Used to separate a solvent from solution
How does Fractional Distillation work and what is its purpose?
The liquids are separated in the column as they boil at different temperatures. One liquid boils at a lower temperature so will condense into the container while the other stays in the column.
What is an atom?
The smallest particle of a chemical element that can exist.
What does (s) mean in state symbols?
Solid
What does (l) mean in state symbols?
Liquid
What does (g) mean in state symbols?
Gas
What does (aq) mean in state symbols?
Aqueous solutions (substances dissolved in water)
Why do all symbol equations have to be balanced?
Because the total mass of the products formed in a reaction is equal to the total mass of the reactants
(Law of conservation of mass)
magnesium + oxygen > what?
magnesium oxide
sodium + chlorine > what?
sodium chloride
Potassium + water > what?
Potassium hydroxide + hydrogen
What is Oil Rig?
Oxidation is loss, Reduction is gain.
