C02) THE PERIODIC TABLE
Metals and non metals
Development
of the Periodic table
The Periodic table
Group 0
Group 1
Group
7
Transition metals (Chemistry only)
H
Li
Na
K
Rb
Cs
Fr
Be
Sc
Ti
Mg
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
Se
Br
Ca
Kr
Y
Zr
Nb
Mo
Tc
Ru
Pd
Ag
Cd
In
Sn
Sb
Sr
Te
Rh
Ba
Hf
Ta
W
Re
Os
Ir
Au
Hg
Tl
Pb
Bi
Po
La
At
Pt
Ra
Rf
Db
Sg
Bh
Hs
Mt
?
?
Ac
?
Al
P
N
O
S
Cl
F
Ne
Ar
Rn
I
Si
Xe
He
B
C
As
1
2
3
4
5
6
7
0
Elements arranged in order of atomic number | Elements with similar properties are in columns called groups | Elements in the same group have the same number of outer shell electrons and elements in the same period (row) have the same number of electron shells. |
Metals to the left of this line, non metals to the right
Noble gases
Alkali metals
Halogens
Transition metals
Before discovery of protons, neutrons and electrons | Elements arranged in order of atomic weight | Early periodic tables were incomplete, some elements were placed in inappropriate groups if the strict order atomic weights was followed. |
Mendeleev | Left gaps for elements that hadn’t been discovered yet | Elements with properties predicted by Mendeleev were discovered and filled in the gaps. Knowledge of isotopes explained why order based on atomic weights was not always correct. |
Metals | To the left of the Periodic table | Form positive ions. Conductors, high melting and boiling points, ductile, malleable. |
Non metals | To the right of the Periodic table | Form negative ions. Insulators, low melting and boiling points. |
Noble gases | Unreactive, do not form molecules | This is due to having full outer shells of electrons. |
Boiling points increase down the group | Increasing atomic number. |
Alkali metals | Very reactive with oxygen, water and chlorine | Only have one electron in their outer shell. Form +1 ions. |
Reactivity increases down the group | Negative outer electron is further away from the positive nucleus so is more easily lost. |
With oxygen | Forms a metal oxide | Metal + oxygen 🡪 metal oxide | e.g. 4Na + O2 🡪 2Na2O |
With water | Forms a metal hydroxide and hydrogen | Metal + water 🡪 metal hydroxide + hydrogen | e.g. 2Na + 2H2O 🡪 2NaOH + H2 |
With chlorine | Forms a metal chloride | Metal + chlorine 🡪 metal chloride | e.g. 2Na + Cl2 🡪 2NaCl |
Halogens | Consist of molecules made of a pair of atoms | Have seven electrons in their outer shell. Form -1 ions. |
Melting and boiling points increase down the group (gas 🡪 liquid 🡪 solid) | Increasing atomic mass number. | |
Reactivity decreases down the group | Increasing proton number means an electron is more easily gained |
With metals | Forms a metal halide | Metal + halogen 🡪 metal halide e.g. Sodium + chlorine 🡪 sodium chloride | e.g. NaCl metal atom loses outer shell electrons and halogen gains an outer shell electron |
With hydrogen | Forms a hydrogen halide | Hydrogen + halogen 🡪 hydrogen halide e.g. Hydrogen + bromine 🡪 hydrogen bromide | e.g. Cl2 + H2 🡪 2HCl |
With aqueous solution of a halide salt | A more reactive halogen will displace the less reactive halogen from the salt | Chlorine + potassium bromide 🡪 potassium chloride + bromine | e.g. Cl2 +2KBr 🡪2KCl + Br2 |
Compared to group 1 |
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Typical properties |
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