Principles of chemistry Flashcards
Properties of a solid?
forces between particles, particle positioning, type of shape, movement
Strong forces of attraction between particles
Fixed positions in lattice arrangement
Keep definite shape and volume
vibrate about positions
Properties of liquids?
forces between particles, type of shape, movement
Weak forces of attraction between particles
Don’t keep a definite shape, but do keep a definite volume
Moving with random motion
Properties of gasses?
forces between particles, type of shape, movement
Forces of attraction between particles are very weak
Don’t have definite shape or volume
Moving constantly with random motion
What’s going from a solid to a gas called?
Subliming
How do states change from to another?
Gain energy, so they vibrate more and break or weaken the bonds
What’s diffusion?
The gradual movement of particles from an area of high concentration to low
What can you use to show diffusion?
Potassium manganite in water, bright purple spreads out
How can ammonia and hydrogen chloride show diffusion?
Put at 2 sides of a tube, white ring will form where they meet, closer to hydrogen chloride, because ammonia diffuses faster
What happens when bromine gas (brown) mixes with air in a tube?
Bromine diffuses making the air browner
Features of a nucleus?
location, what it contains, what charge, mass
Middle of atom
Contains protons and neutrons
Positive charge due to protons
Small compared to rest of atom, but contains all mass
Features of electrons?
Move around the nucleus in shells
negatively charged (-1)
Very small
No mass
Features of protons?
Relative mass=1
Relative charge = 1
The number of protons equals?
The number of electrons
Features of a neutron?
Relative mass=1
No charge
What’s the mass number?
Total number of protons and neutrons
What’s the atomic number?
Number of protons
How do you find the amount of neutrons?
Mass number subtract atomic number
What are molecules?
Groups of atoms held together by covalent bonds
Elements consist of?
1 type of atom
What’s a diatomic molecule?
A molecule with 2 atoms
What’s a compound?
2 or more different elements chemically bonded together
What’s a mixture?
When there’s no chemical bond between parts, and they can be separated by physical methods
What’s filtration used for?
To separate an insoluble solid from a liquid (filter paper)
What’s crystallisation used for?
Separating a soluble solid from a soloution
Method for crystallisation?
Pour solution into evaporating dish
Heat solution
Place in warm place to allow evaporation from the crystals
Dry in drying oven
How can you use filtration and crystallisation to separate rock(Insouluble)Salt(solouble)?
Grind up
dissolve in beaker
Filter
Crystallise
What’s paper chromatography?
Putting dots of ink on a piece paper, placing it in a solvent and seeing how soluble the dyes are by how far they move up the paper
What’s simple distillation used for?
Separate solutions
What’s fractional distillation used for?
Separating a mixture of liquids, different boiling point come out at different fractions
What are groups on the periodic table?
Amount of outer electrons
What are group 1 elements called?
alkali metals
What are group 7 elements called?
halogens
What are group 0 elements called?
Noble gases
What are the electron shell rule?
they fill up shells in the form 2:8:8
Happiest when they have a full shell
Want to react when it’s not full
What’s ionic bonding?
When atoms bond and lose or gain electrons to become strongly attracted to each other through electrostatic attraction
What’s oxidation?
When an atom loses electrons
What’s reduction?
When an atom gains electrons
What are positive ions called?
Cations
What are negatively charged ions called?
Anions
When does ionic bonding occur?
When an atom wants to get rid of electrons, and another atom wants to gain an electrons
Why do giant ionic structures have high melting and boiling points?
closely packed 3D lattice arrangement,
oppositely charged ions mean strong forces if attraction
What’s covalent bonding?
When atoms share electrons to fill each others outer shell
What are the atoms within a molecule bonded by?
Strong covalent bonds