Gold foil experiment Flashcards
What was the gold foil experiment and what did it prove?
The majority of the alpha particles that Rutherford fired at the gold foil passed straight through the piece of foil, proving that the atom is mainly empty space. Some alpha particles were deflected near the centre, this proves that there is a positively charged centre in the atom (as like charges repel) known as a nucleus where most of the mass is concentrated.
What is crystallisation?
Crystallisation is the process of forming solid crystals from a solution.
Method:
-the solution is heated in an open container. the heat source varies, if you’re using an inflammable solvent like water, use a bunsen burner, however if you’re using a flammable solvent like ethanol, you’d use an electric heater or water bath bc u don’t want a flame near it
-the solvent molecules start evaporating, leaving behind the solutes
-when the solution cools, crystals of solute start accumulating on the surface of the solution
-crystals are collected and dried
What is filtration
Filtration is used to separate an insoluble substance from a liquid
What does the group number tell u in the periodic table
The group number of each element tells us how many electrons are in the outer shell
What does the period number (rows) tell u in the periodic table
The period number tells u how many shells are in the electron configuration
What is an isotope
Atoms of the same element which have different mass numbers. This is because they have the same amount of protons but a different amount of neutrons.
What is the symbol for relative atomic mass (atomic mass)
Ar
Equation of Ar
(mass x abundance) + (mass x abundance) /100
Why do u not use ink and use pencil to draw the line in chromatography
Pencil is insoluble in water and will not move as the chromatography progresses, whereas pen ink is soluble in water, and the pen ink will dissolve and mix with the samples being tested
What do the dots in chromatography represent
A pure substance produces 1 spot, and impure substance produces 2 or more spots
What is effervescence
Effervescence is the formation of gas bubbles in a liquid due to a chemical reaction.
What is the conservation of mass
Mass is neither created nor destroyed in chemical reactions
Radius of an atom
0.1 nanometers (1x10^-10m)
Radius of the nucleus
Less than 1/10,000 the size of an atom. (About 1x10^-19m)
Electron configuration
The first shell holds up to 2 electrons, the second and third shells hold up to 8 electrons, and any other shells hold any extra electrons. There is no limit for the amount of shells an atom has.
