C1: Atomic Structure Flashcards
How are compounds formed?
From elements by chemical reactions
What did the discovery of the electron lead to?
The plum pudding model
What did the plum pudding model state?
The atom is a small ball of positive charge with negative electrons embedded
What 2 things did the results from the alpha scattering experiment lead to?
The mass as concentrated at the centre (a nucleus) and that the nucleus was charged
Who adapted the nuclear model? (a.k.a the alpha scattering experiment)
Niels Bohr
How was the nuclear model adapted?
The suggestion that electrons orbited the nucleus at specific distances
What did James Chadwick do?
Discover neutrons
What is an elements atomic number?
The number of protons
What is the radius of an atom?
0.1nm
What is the radius of a nucleus?
1/10,000 of that atom
Where is almost all of the mass of an atom be?
The nucleus
What is the mass number?
The sum of an atom’s protons and neutrons
What is the mass number?
The sum of an atom’s protons and neutron
What is the relative atomic mass of an atom?
The average value that takes account of the abundance of the isotopes of the element
What does the size of an atom depend on?
The element that it is
What is a molecule?
2 or more atoms that are held together by chemical bonds
What does filtration separate?
Insoluble solids from liquids
What is an advantage and a disadvantage of evaporation as a separating technique?
It is quick, however some solids decompose when heated; thermal decomposition
Describe how the process of crystallisation will be carried out
Heat solution with a bunsen burner until crystals form. Allow to cool to form more crystals and then rest for water to evaporate or filter. Lastly dry crystals in an oven
What does simple distillation separate?
Liquids from solutions, e.g. pure water from sea water
What is the function of the glass rods in fractional distillation?
They provide a high surface area
What are 2 properties of the fractionating column?
Cooler at the top and has glass rods
What did John Dalton describe atoms as?
Solid spheres
Who came up with the plum pudding model?
JJ. Thompson
How does the electron’s orbit help the atom?
It prevents it from collapsing
