C1 - Atomic Structure Flashcards
What is a mixture?
Two or more substances not chemically combined together.
What is a compound?
Two or more substances that are chemically combined together.
What is filtration?
Seperating insoluble chemicals from a mixture by using filter paper.
What is crystallization?
Boiling water underneath a solution to evaporate the liquid (solvent) in a mixture.
What is distillation?
Seperating a soluble solid from a substance via heating, whilst collecting the liquid (solvent) via a cooled glass pipe.
What is fractional distillation?
Seperating two liquids in a mixture by abusing the differing boiling points between the two liquids, e.g. boiling an ethanol and water mix at 80 degrees to only evaporate the ethanol.
What is chromatography?
Dotting a solution on chromatography paper, placing the very bottom in water and using the travel of the solution up the paper to calculate the concentration of certain elements in a solution.
What is the plum pudding model?
An atom represented as negative plums (electrons) in a sea of positive charge.
How was the nucleus discovered?
- Alpha particles fired at gold foil, expected to pass straight through particles.
- Instead were often rebounded, meaning the positive charge was concentrated at a tiny, central point - the nucleus.
What is an ion?
A charged atom.
How is an ion formed?
When a bond is formed, an atom will gain or lose electrons to form a full outer shell. This loss or gain of electrons results in a change in charge, forming an ion.
What is an isotope?
An atom with a changed number of neutrons, resulting in a changed atomic weight. These may be radioactive, but always maintain the same chemical properties as their non-isotope counterparts.
What is the number of electrons in each shell for the first 3 shells?
2, 8, 8
Why are atoms with more electrons less stable?
As electrons get further out, the pull of the nucleus on them gets weaker, making them easier to knock off, and making them less stable.
