C1 Key Concepts in Chemistry Flashcards
What did JJ Thomson conclude about the structure of an atom?
Atoms were small spheres containing electrons in a ‘plum pudding model’
What did Ernest Rutherford do?
He fired positive alpha particles at an extremely thin gold sheet. Some were slightly deflected and very little were deflected straight back. The nuclear model was then created
What did Niels Bohr do?
He proposed a new model where electrons orbited the nucleus in shells
What is the atomic number?
The number of protons in an element
What is the mass number?
The number of protons and neutrons in an element
What is an isotope?
A different form of the same element with the same number of protons but a different number of neutrons
What is the relative atomic mass?
The average mass of one atom of the element compared to 1/12 of the mass of one atom of carbon-12
How did Mendeleev order the first periodic table?
By order of atomic mass
How is the modern periodic table ordered?
By atomic number
What is an ion?
Charged particles
What is ionic bonding?
When a metal and a non-metal react together to form a strong compound held together by electrostatic forces
What is covalent bonding?
A bond that forms when a pair of electrons is shared between two atoms
What are the properties of diamond?
- Very hard
- High melting and boiling points
- Insoluble
- Doesn’t conduct electricity
What are the properties of graphite?
- Soft and slippery
- High melting and boiling points
- Insoluble
- Does conduct electricity
What are the properties of buckminsterfullerene?
- Black solid
- Semi conductor
What are the uses for diamond?
Strengthening cutting tools
What are the uses of graphite?
Lubrication
What is metallic bonding?
The electrostatic force between metal ions
What are the properties of metals?
- High melting and boiling points
- High density
- Malleable
- Good conductors of heat and electricity
