Zusammenfassung der Ressource
C3.1 The Periodic Table
- The Early Periodic Table
- 19th
Century -
elements
found every
year, so they
tried to find
patterns
- John Dalton arranged
in order of masses
- 1864 -John Newlands
built on Dalton's ideas
with the rule of octaves
- Properties of
every 8th
Element were
similar
- Assumed all
elements had
been found
- Mendeleev
- 1869 - Dmitri
Mendeleev
placed in order
of atomic weight
and arranged to
create a pattern
- Left Gaps
- The Modern Periodic Table
- Some of
Mendeleev's table
had faults
- Some didn't fit the pattern
- Some had
odd
properties
- 20th century -
learned more
about structure of
the atom
- Began
arranging
by proton
number
- Groups
- react
in
similar
ways
- Outer shell has
same number of
electrons
- Group
number tells
us what this
number is
- As we go
down the
group, the
atom gets
bigger
- Lose and Gain
electrons
easily
- Further away from
the neucleus
- Group 1 - Alkali Metals
- Contains:
- Li
- Na
- K
- Rb
- Cs
- Fr
- Radioactive
- Properties
- Extremely reactive
- Stored in oil or
reaction with
air occurs
- Low density
- Soft
- Shiny before
reaction with air but
oxide soon is made
- Lose 1 electron to
become a noble gas
- React with non metals
- Form an ion of 1+ charge
- Form ionic
compounds
- Low
boiling
point
- Reaction with Water
- Fizzing
because of
hydrogen
- K creates
lilac flame
- Metal hydroxide
- soluble
- solution with
a high pH
- Other Reactions
- With chlorine
makes metal
chloride
- Ionic compounds of
alkali metals are
usually white
- Transition Elements/Metals
- Physical Properties
- Conduct
electricity and
energy
- Hard and
strong
- Very
dense
- High melting point
- Chemical Properties
- Not as
reactive
as group
1.
- Corrode Slowly
- Good structural properties
- Compounds of
the metals
- Coloured compounds
- Transition elements can form
more than one ion (hence the
roman numeral)
- Useful as catalysts
- Group 7 - The Halogens
- Properties
- Poisonous non metals
- coloured
vapour
- Low Melting and
Boiling points
- Poor conductors
- Reactions
- 7 outer
shell
electrons
- Both ionic and
covalent bonding
- With metals
- Non metals gives
covalent bond
- Displacement Reactions
- Use a more reactive
halogen to displace another
from a salt solution