C1 - Atomic structure Flashcards
What are some ways of seperating mixtures?
Filtration
Crystalisation
Distillation
Chromatography
What was JJ Thompsons discovery in 1897?
The Plum Pudding Model
What was the plum pudding model idea?
That an atom was a ball of positive charge with electrons in it
What did Bohr propose in 1913?
That the electrons orbit the nucleus
What did Rutherford discover after his previous nuclear model was incorrect?
Protons
Lastly, What did James Chadwick discover?
neutrons
What is the relative mass of a proton?
1
What is the relative mass of a neutron
1
What is the relative charge of an electron
-1
What is the atomic number?
The amount of protons the element has
How do you calculate the mass number of an element?
Protons + neutrons
What is an isotope?
Atoms with the same number of PROTONS but DIFFERENT number of NEUTRONS
How does an atom turn into a positive ion? (Ionization)
If an electron in the outershell gains too much energy it will leave the atom
There will be more protons than electons
So it becomes a positive ion
What do ‘subatomic particles’ refer to?
Protons, Neutrons, Electrons
What is the relative charge of a proton?
+1
What is the relative charge of a neutron?
0
What is the relative mass of an electron?
0.0005
What did Rutherford propose?
There was some sort of compact nucleus
What is Filtration?
The technique that separates insoluble solids from liquids
What is an example of a filtration experiment? What is the insoluble substance? What is the soluble substance? And what is the solvent?
Experiment of seperating SALT and SAND mixture
Solvent = water and salt mixed
Insoluble = sand (cannot be dissolved)
Soluble = salt
What does the term ‘mixture’ include in seperation techniques?
A liquid and an insoluble solid
What is an example of a ‘mixture’ in seperation techniques and why?
Sand in Water
because the sand does not dissolve in the water
What does a ‘Solution’ include in seperation techniques?
A liquid and a soluble solid
What is a solvent?
A liquid that is capable of dissolving one or more substances
What is crystallisation?
The technique that seperates a soluble substance from a solvent, by heating
What is distillation?
The technique that seperates a liquid from a mixture by evaporation, followed by condensation
What is fractional distillation?
The technique that seperates a mixture into a number of diffrent fractions (parts)
Where would you find the mass number of an element symbol?
The TOP number
Where would you find the atomic number on an element symbol?
The BOTTOM number
What did John Dalton’s think the Atomic model consisted of?
An atom was a solid sphere that could not be divided. (No subatomic particles)
Why do atoms have no overall charge?
They have an equal number of protons and electrons
What did scientists discover in the alpha scattering experiment?
Some alpha particles were deflected by the gold foil
What did the Alpha scattering experiment conclude to?
An atoms mass and positive charge must be concentrated in a nucleus
What is the atomic theory?
The idea that everything is made up of tiny particles seperated by empty space
Who founded the atomic theory?
Democritus (500 BC)
How do you calculate the relative atomic mass of an isotope?
Multiply the % abundance of each isotope with its mass
Add them together and then divide by 100 (%)
Why do atoms have only 2 electrons in its innermost shell?
The innermost shell can only hold 2 electrons
Suggest 2 reasons why a discovery of an element like Gallium helped Mendeleevs Periodic table become accepted
Gallium fit a gap that Mendeleev had left
Galliums properties were predicted correctly
What is one limitation of using a dot and cross diagram to show a molecule?
Its only in 2D and not 3D
How did Niehl Bohr adapt the Nuclear Model?
He made the electrons orbit the nucleus
Electrons had a specific distance from the nucleus
