Atomic structure and the periodic table and bonding/structure. Flashcards
What is an atom?
An atom is the smallest part of an element that can exist.
What is an element?
An element is a substance that contains only 1 type of atom.
What are compounds?
A compound contains atoms of 2 or more elements that are chemically combined.
How can compounds be separated?
By chemical reactions or
electrolysis.
Why does the mass of products and mass of reactants equal the same?
Because no atoms are lost or made.
What is a mixture?
A mixture is 2 or more elements/compounds which are not chemically combined.
What is Filtration used to separate?
Soluble solids from insoluble solids.
What is Crystallisation used to separate?
To slowly separate a soluble salt from a solution.
What is simple distillation used for?
Separating a liquid from a solution.
What is the practical for simple distillation?
1) Use a pH probe to analyse the pH of the sample.
2) Set up the equipment.
3) Heat the water to 100 Celsius so that the water goes from liquid to gas.
4) The water collects in the condenser and changes from a gas to a liquid. Collect this pure water in a beaker.
5) When all the water has evaporated measure the mass of the solid that remains to find the amount of solid present.
What is fractional distillation used to separate?
To separate out mixtures (usually liquids).
What is chromatography used for?
Used to separate the different soluble coloured components of a mixture.
Who discovered the plum pudding model and when did they discover it?
Discovered by JJ Thompson in 1897.
What was in the plum pudding model?
Negative electrons surrounded by a sea of positive charge.
What happened to the alpha particles in the Marsden and Geiger experiment?
Most passed through and some deflected back.
What results did Rutherford conclude?
That the positive charge in an atom must be concentrated in a very small area This was named the nucleus.
What model replaced the plum pudding model?
The nuclear model.
Who discovered neutrons?
James Chadwick.
What is the radius of an atom?
0.1 Nanometre.
What are the relative masses of Protons, Neutrons and Electrons?
1,1 and very small.
What is the relative charge of a Proton, Neutron and Electron?
+1, 0 and -1.
How do you work out the number of neutrons?
Mass number - Atomic number.
What is an isotope?
Isotopes of an element have the same number of protons but a different number of neutrons.
What type of ions do metals form?
They lose electrons to form positive ions.
What type of ions do non-metals form?
They gain electrons to form negative ions.
What is electron configuration?
The electron configuration of an atom shows how the electrons are arranged around the nucleus in shells.