P1 - Atomic Structure And The Periodic Table Flashcards
Define an ion
An ion is a charged particle, it’s number of protons doesn’t equal its number of electrons.
Define an isotope
An isotope is an element with the same number of protons but a different number of neutrons
Give examples of mixtures
- Air (mixture of gases mainly nitrogen oxygen carbon dioxide and argon)
- Crude oil (mixture of different hydrocarbon molecules)
Describe how to set up the paper chromatography practical
- Draw pencil line a cm from the bottom of the chromatography paper
- Add ink spots on the pencil line
- Put a solvent in a beaker (eg water)
- Put the paper into the solvent making sure the inks don’t touch the solvent
- Watch the dyes separate
Define filtration
Filtration is used when an insoluble solid needs to be separated from a liquid reaction mixture. You put filter paper into a funnel and pour the liquid with the solid into it. The liquid will pass through into the beaker and the solid will be left.
Define evaporation practical
Evaporation is used when the solid is dissolved into the liquid (is soluble). You pour the solution into an evaporating dish and heat it using a Bunsen burner. The liquid will evaporate leaving dry crystals of the original solid.
Define crystallisation practical
If the salt decomposes when heated you use crystallisation instead of evaporation. You pour the solution into an evaporating dish and heat it. When you see some crystals starting to form remove it from the Bunsen burner and filter the crystals out as they are now insoluble.
Define distillation
Distillation is used to separate a liquid from a solution.
Simple distillation - heat solution then out through a condenser which turns it into a liquid
Fractional distillation - separates multiple liquids. When you heat crude oil and fill the fractionating column with glass rods, at different levels of the column you place a condenser which at each level gives out a different liquid.
What did each of these scientists do to contribute to the structure of the atom:
- John Dalton
- JJ Thompson
- Ernest Rutherford
- Niels Bohr
John Dalton - thought atoms were solid spheres.
JJ Thompson - came up with the plum pudding model with positively charge atom filled with negative electrons
Ernest Rutherford - did the alpha particle scattering experiment. Fired alpha particles through a gold sheet and expected them all to pass through but some were deflected by the nucleus which shows that most of an atom is empty space and positive charge is in a nucleus.
Niels Bohr - came up with the nuclear model that electrons were in shells.
How is the periodic table arranged?
In increasing atomic number
What did Dmitri Mendeleev do?
He created the Table of Elements leaving gaps for undiscovered elements. He put them in order of atomic mass, but also considered their properties so that he could arrange them into groups.
Define metal
An element that can form a positive ion when they react. These are on the left of the periodic table.
Define non-metal
Elements that form negative ions when they react. They are on the right of the periodic table.
How do the electronic structures of atoms affect how they gain or lose electrons.
Atoms on left - more shells means more reactive because electron is further from nucleus making attraction weaker, easier to lose.
Atoms on right - less shells means more reactive because less of a barrier for attraction of electron to nucleus, easier to gain.
What are the properties of a metal?
- Shiny
- Strong
- Malleable
- Good conductors of heat and electricity
- High melting and boiling points
