C1: Atomic Structure Flashcards
What are atoms?
The smallest existing part of an element.
What is an element?
Made up of only one type of atom.
What are the two categories elements are split into?
Metal and non-metal.
What are elements displayed in?
Periodic table
What is the vertical column called for elements?
Group
What is the horizontal row used for elements?
Period
What are the elements that lie next to the ‘staircase’ of non-metals and metals?
semi-metals, containing both metallic and non-metallic properties.
Examples of semi-metals?
Silicon, germanium
What is a compound?
Two or more elements that are chemically bonded together.
Describe atomic structure:
Concentrated positive nucleus with electrons orbiting around it in ‘shells’.
What is at the start of a chemical equation?
Reactants
What is at the end of a chemical equation?
Products
Law of conservation of mass
The total mass of the products formed in a reaction is equal to the total mass of the reactants.
Why might the law of COM seem false?
Mass can ‘disappear’ in gases, as they escape into the air.
4 state symbols and what they mean:
(s) - solid
(l) - liquid
(g) - gas
(aq) - dissolved in water (aqueous)
What must be used in order to separate the elements in a compound?
Chemical reactions
What is a mixture?
Made up of two or more substances that are not chemically combined together.
4 ways to separate mixtures:
-Filtration
-Crystallisation (or evaporation)
-Distillation (fractional or simple)
-Chromotography
Compounds have a fixed ________
composition
Describe filtration:
Used to separate substances that are insoluble in a particular solvent from those that are soluble in the solvent.
An example of filtration:
Sand and water
Describe crystallisation:
Obtaining a soluble solid from a liquid.
example of evaporation:
salt and water (saltwater)
Process of crystallisation
-Heat evaporating dish with salt solution over a waterbath, bunsen and gauze.
-Heating stop when the first crystals appear.
-Leave rest at room temperature and crystals should form.
Distillation, explain
Separates a soluble solid from a solvent, also collecting the solvent itself.
Describe simple distillation:
-Solution heated and boiled to evaporate solvent.
-Vapour trapped in condenser and is carried down to a beaker as a liquid.
-Dissolved solids now solid remaining in heated flask.
What does fractional distillation do?
Separates mixtures of miscible liquids by using their boiling points.
What does miscible mean?
Liquids that dissolve in each other, mixing completely.
What equipment is used in fractional distillation?
Fractionating column
What is paper chromatography used for?
To separate and identify substances from a mixture.
Describe the process of paper chromatography:
-Capillary tube to dab a spot of each solution on the paper (stationary phase).
-Placed in beaker, pencil line insoluble ect.
-Solvent placed on the paper just below the pencil line.
-Solvent (mobile phase) carries substances through paper, separating them.
Relative charges of sub atomic particles
P-1
N-0
E–1
Relative mass of sub atomic particles
P-1
N-1
E-0 (very small)
What is atomic number?
Number of protons
What is mass number?
Neutrons and protons
How to work out number of neutrons?
Mass number - atomic number
What is an ion?
Charged atom or group of atoms?
What charge of ions do metals form?
Positive (loses electrons)
What charge of ion do non-metals form?
Negative (gains electrons)
What is an isotope?
Atoms of the same elements with the same number of protons, but a different number of neutrons.
Danger of some isotopes:
Unstable isotopes can be radioactive.
How to find out average isotope number:
(abundance x relative atomic mass) /100
+
(abundance x relative atomic mass) /100
Limits of each electron shell?
2,8,8,8,8 (you get it)
