1. C1 Topic 1: The Earth’s Sea and Atmosphere
This topic looks at:
How the early atmosphere and oceans were formed
How levels of carbon dioxide reduced and levels of oxygen increased
The impact of volcanic and human activities on the atmosphere
Carbon Dioxide in the Atmosphere
The constant recycling of carbon is called the carbon cycle.
Draw the carbon cycle:
Global Warming
The level of greenhouse gases in the atmosphere has gradually increased as a result of: 1. 2. 3. 4.
Draw or write the timescale from the formation of Earth to how it is now:
Draw or write the composition of the Atmosphere has changed from the formation of the Earth to now:
Oxygen in the Atmosphere
The levels of oxygen in the atmosphere have changed throughout the history of the Earth.
Below briefly explain how:
Keywords: Oceans, Water Vapour, Photosynthesis,
Draw or write key factors and events that shaped the atmosphere
Put the following in the correct order (Number them)
The burning of fossil fuels also releases carbon dioxide into the air
Plants and animals respire, releasing carbon dioxide into the atmosphere
Carbon dioxide is removed from the atmosphere by green plants during photosynthesis
Microorganisms feed on dead plants and animals, causing them to break down, decay and release carbon dioxide into the air.
Keywords: Carbon dioxide, Nitrogen, Carbon Cycle, Global Warming, Fossil Fuels, deforestation.

2. P1b) Radiation & the Universe
Structure of the atom
Nuclear radiation
deflected in magnetic and electric fields helium nucleus deflected in magnetic and electric fields electron
Not deflected e.m. wave
Thickness control half life years
Beta radiation
PROTON – positive, same mass as neutron (“1”)
NEUTRON – neutral, same mass as proton (“1”)
ELECTRON – negative, mass nearly nothing
Half – life
Time it takes for number of radioactive nuclei/count rate to fall to half its initial value
Half lives
Tracers half life hours
Gamma radiation
100
200
Activity
Time (s) 5 10 T 2T 3T 4T
P1b) Radiation & the Universe
Keywords: radiation, half-life, proton, neutron, electron, isotope, alpha, beta, gamma
Isotopes
Penetrating power
In air :
α- 5cm
β- 1m
γ - km
Ionising power
Alpha – very
Gamma - weakly
Smoke Alarms – half life years
Alpha radiation
Smoke detectors
Keywords: ionising, penetration, range, tracer