Science-Chemistry
What is element
A substance made from just one type of atom
What is a compound
A substance made up of two or more different chemical elements chemically combined in a fixed ratio.
What is a mixture
A substance made up from two or more different types of atom not chemically combined together
What is it called when gas turns into liquid
condensation
What is it called when liquid turns into gas
evaporation
What is the boiling point of water
100 degrees celcius
What was 1.Dalton's model of an atom
A solid sphere containing no sub atomic particles
What was 2.Thompson's plum pudding model of an atom
A sphere of positive charge containing electrons spread evenly throughout
What was 3.Rutherford's Nuclear model of an atom
A positive central nucleaus with electrons orbiting around (the film one)
What was 4.Bohr's planterary model of an atom
the one now but with no neutrons
What was 5.Chadwick's model of an atom (modern one)
Same as Bohr's but discovered neutrons in the nucleus
What is the charge of a PRO ton
+1 and mass 1
What is the charge of a NEUTR on
0 and mass 1
What is the charge of a electron
-1 and mass 1/2000
How do you calculate the number of neutrons
mass number-atomic number / top-bottom = number of neutrons
What do atoms have the same number of
PRO tons ans electrons
How do you know how many electrons there are on the outer shell
for which group the element is in that equals the amount of electrons there are on the outer shell
Which group have a full outer shell on the periodic table
group 0
What did Dobereiner (English) suggest (law of the triads) 1. 1817
In the periodic table there should be groups of threes that each have their own similar chemical properties
What did Newlands (German) suggest (law of the octaves) 2. 1864
There was a similarity within chemical properties every eighth element (lithium,sodium and pottasium all react with water similarly)
What did Mendeleev (Russian) suggest 3. 1869
He put them in order of atomic mass/weight increasing order he also left gaps for undiscovered elements.
Why was Mendeleev's theory so important 3. 1869
Because he predicted some of the elements that have been found today (with similar properties)
What is the modern name for atomic weight
relative atomic mass
How many shells can fit into an atom
1. 2 2. 8 3. 8 4. 16