C1 - Atomic Structure and the Periodic Table Flashcards
How big is an atom?
1 X 10^-10
State five facts about the nucleus.
1) It’s in the middle of the atom.
2) It contains protons and neutrons.
3) The nucleus has a radius of 1 X 10^-14 (1/10,000 of the radius of an atom).
4) It has a positive charge (because of the protons).
5) Almost all of the mass of an atom is found in the nucleus.
What is the mass, charge and position of protons, neutrons and electrons?
Protons - 1g, +1, nucleus.
Neutrons - 1g, 0, nucleus.
Electrons - 0 or negligible, -1, energy levels.
How do you calculate the amount of neutrons in an atom?
Subtract the atomic number from the mass number.
What is an element?
A substance made up of the same atoms.
Elements consist of atoms with the same?
Atomic number.
What is an isotope?
They have the same number of protons, but a different number of neutrons. This means that they have the same atomic number but different mass numbers.
How do you calculate relative atomic mass?
Sum of (isotope abundance X isotope mass number)
———————————————————
Sum of abundances of all the isotopes
What is a compound?
Substances made up of two or more elements and are held together by chemical bonds.
What does a compound which is formed from a metal and non metal consist of?
Positive and negative ions which have a strong electrostatic force of attraction between each other.
What do chemical equations show?
Chemical changes.
What is a mixture?
A group of substances that aren’t chemically bonded together.
What is chromatography used for?
Separating different dyes in an ink.
Describe the chromatography practical.
1) Draw a base line near the bottom of a sheet of chromatography paper. This must be done in pencil so it doesn’t dissolve in the solvent.
2) Add a spot of ink to the base line and place the sheet in a beaker of solvent (such as water).
3) Make sure the base line doesn’t touch the solvent so the ink doesn’t dissolve into it.
4) Place a lid on top of the container to stop the solvent evaporating.
5) The solvent should then seep up the paper, carrying ink with it.
6) If a dye is insoluble, it will stay on the base line. This is because the more soluble the dye, the further up the paper it moves.
7) When the solvent has nearly reached the top of the paper, take the paper out and leave it to dry.
8) The end result is called a chromatogram.
What does filtration separate?
Insoluble solids from liquids.
Describe filtration.
1) Fold the filter paper into a cone shape.
2) Place the filter paper into a funnel.
3) Place the funnel into a beaker.
4) Pour the mixture into the funnel.
5) The insoluble solid wouldn’t flow down the tube, so it is separated from the liquid.