1. Structure Flashcards
heterogenous
substance where each component exists in clumps. You can also see induvidual components. e.g. oil and water
homogenous
Substance where each component is evenly distributed. Difficult to identify the induvidual components. e.g. coffee
distillation
seperates solvent from a solution
filtration
insoluble solid from liquid
crystallisation
Seperating solute from a solution
chromatography
e.g. ink or coloured compounds
fractional distillation
seperates a mixture using boiling points
Solvation
Seperating insoluble + soluble solids using a solvent
Limonene
An organic compound found in the rinds of citrus fruits.
- strong aroma
- has potential health benefits but no groundbreaking evidence
Qualitive
Quality, anything that can be detected by senses
Quantitive
quantity
Gas to solid
Deposition
Solid to gas
Sublimation
Are kelvin and Celsius the same kind of scale?
Yes kelvin starts a 0 and goes up to 373.15 where water boils (373.15 diff)
Celsius starts at -273.15 and goes to 100 where water boils (373.15 diff)
What are the limitations of the particle model?
- Particles aren’t moving
- only pure substances taken into account
How do nuclei of atoms differ?
- Different number of protons.
- elements have same proton number but different nucleon number which is an isotope.
What did Democritus propose?
Proposed all matter was made up of smaller unites named “atomos” meaning invisible
What did JJ Thompson discover?
In 1906 he discovered the electron thinking it was in the nucleus with protons.
Made a model known as the plum pudding model
What was the gold foil experiment and what were the findings?
The gold foil experiment was where alpha particles (He2+ particles) were fired into gold foil and there was a large screen to record findings. Very rarely almost 1 in 20,000 the particle would repel or even come back to where the alpha particle were fired. Happened in 1911
WHAT DID THESE FINDINGS SUGGEST?
- Most of the atom is empty space.
- Positively charged centre with electrons revolving around the nucleus
- Size of nucleus is small compared to size of atom
What did Niels Bohr discover?
Electrons move around a nucleus but only in prescribed orbits (e.g. 2,8 …) like the solar system the electrons orbit the nucleus like we orbit the sun.