Download c1b revision sheet 1[1]

Paper chromatography
Chemical analysis - technique used to identify food additives.
Separates substances in a mixture based on how well they
dissolve in a solvent. The solvent e.g. water or ethanol
carries the dye up the paper separating them
Retention factor = distance moved by the substance/
distance moved by the solvent
The Earth is made up of 3 layers - crust,
mantle and core
crust - relatively thin and rocky.
mantle - has the properties of a solid, but
can flow very slowly.
outer core - made from liquid nickel and iron
inner core - made from solid nickel and iron
The Continents
Supercontinent of Pangaea - 250 million years ago
100 million years ago - Pangaea split into 2.
The land continued to move until 50 million years ago.
Continents move a few cm’s every year.
The Earth’s lithosphere is cracked into tectonic
plates, which are constantly moving.
Convection currents push the tectonic plates
over the surface of Earth, due to radioactive
decay.
Earthquakes can occur at the plate boundaries
because huge forces push the plates against
each other.
Volcanoes form at weak points in the Earths
crust
C1b Chemistry
The lithosphere includes the crust
and the uppermost mantle, which
constitute the hard and rigid outer
layer of the Earth.
Ozone (O3) forms a shield against ultraviolet rays.
The levels of greenhouse gases in the atmosphere are thought
to be rising, resulting in climate change.
1.
Sun’s rays enter the Earth’s atmosphere
2.
Heat is reflected back from the Earth’s surface
3.
Heat is absorbed by carbon dioxide (greenhouse gas and
as a result becomes trapped in the Earth’s atmosphere
4.
The Earth becomes hotter as a result
The air is a mixture of
mainly nitrogen, oxygen ,
variable amounts of water
vapour and very small
amount of other gases
such as carbon dioxide and
the noble gases.
Carbon moves in and out
of the atmosphere due
to plants, the oceans
and rocks.
The amount of carbon
dioxide in the Earth’s
atmosphere has risen
due to the amount of
fossil fuels burnt.
Carbon
cycle has kept
the level of
CO2 in the
atmosphere
steady for the
last 200 million
years.
The Earth’s atmosphere has
changed over millions of years.
Many of the gases that make
up the atmosphere come from
volcanoes. E.g. water vapour,
ammonia, carbon dioxide and
methane.
As plants colonised, the levels
of Oxygen increased.