Atoms 1 (Brett) Flashcards
Democritus
Founded the atoms or ‘atomos’ in greek, and thought all matter was indivisible and that atoms were indestructible, and that they differed in size, shape, mass, position and arrangement
John Dalton
agreed with Democritus, thought all matter was made of atoms, all atoms of elements are identical, all atoms of different elects are different, atoms can’t be created or destroyed (law of conservation of mass), atoms combine in fixed ratios to form compounds (law of definite proportions)
J.J. Thompson
Discovered electrons with the Plum Pudding Model, electron is close to 2000x smaller than the atom, things are inside the atom, atom has electrons and positive body
Ernest Rutherford
Not satisfied with current throes so he did and experiment, he projected a beam of alpha particles to a thin sheet of gold to probe inner structure of the atom, 99% went straight through the atom, 1/6000 deflected and 1/8000 reflected, proved that the atom is mostly empty, with electrons and a positive nucleus
Nucleus and atom size relationship
nucleus is 10000x smaller than the atom
Top number on periodic elements
atomic number
Bottom number on periodic elements
Atomic mass
RAM
Relative Atomic Mass
Proton charge
Positive
Proton mass
1
Electron charge
-1
Electron mass
1/2000
Neutron charge
0
Neutron mass
1
proton to neutron relationship on the periodic table
same amount
atomic number
number of protons
Mass number
Protons & Neutrons
How to work out neutron number
mass number - atomic number
Electron configuration
arrangement of shells
Max electron configuration
2,8,8,18,18…
First 20 elements of periodic table (names)
Hydrogen, Helium, Lithium, Beryllium, Boron, Carbon, Nitrogen, Oxygen, Fluorine, Neon, Sodium, Magnesium, Aluminum, Silicon, Phosphorus, Sulfur, CHlorine, Argon, Potassium, Calcium
First 20 elements of periodic table (symbols)
H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca
Group 1 elements
Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Caesium (Cs), Francium (Fr)
Pattern of elements going down groups
Boiling points reduce, melting points reduce, Density increases, more reactive, atomic radius increases
Metal + Water –>
Metal hydroxide
Why elements further down the table are more reavtive
More shells mean a higher atomic radius, which makes the connection between the electrons and nucleus is worse, hence meaning it is easer lose (or gain) electrons
Hydrochloric acid
HCl
Nitric acid
HNO3
Sulfuric acid
H2SO4
Reactive part of an acid
Hydrogen
Metal Oxide + Acid –>
Salt + Water
Scientific equipment
measuring cylinder, beaker, glass rod, spatula, conical flask, water bath, Bunsen burner, evaporating basin
Acid + Base –>
Salt + Water
Base
Soluble alkali
Copper Sulfate Method
1.Place 75ml of sulfuric acid in a conical flash
2.Add one spatula of copper oxide powder to the acid and stir with a glass rod
3.Add one more spatula of copper oxide and stir for 2 minutes
4.Filter the mixture to remove the excess copper oxide
5.Pour the filtrate (copper sulfate) into an evaporating basin
6.Heat the contents of the evaporating basin gently until about a third of the solution has evaporated
7.Leave the solution to cool and then examine the crystals which are formed. be careful because the crystals are harmful
Titration
neutralizing reactions
Phenolphthalein
Turns purple for alkali/base
Titration method
1.Set up experiment like diagram and wear safety equipment
2.Pour 50ml of HCl acid into the conical flask
3.Add 1-2 drops of phenolphthalein (indicator)
4.Fill up the burette with sodium hydroxide (alkali)
5.Run the alkali through the rube into the acid, and keep stirring the mixture clear
6.Look for a complete color change (mixture is pink/purple)
