atmosphere, water and atoms Flashcards
(32 cards)
what percentage of the air is oxygen
21%
what does it mean when volcanoes degas
they release gases from the centre of the earth
what percentage of the air is nitogen
78%
what percentage of the air is argon
1%
what percentage of the air is carbon dioxide
0.04%
what is the chemical test for oxygen
relights glowing splint
what are the main greenhouse gases
carbon dioxide, methane and water vapour
why are the amounts of co2 increasing
due to the burning of fossil fuels and removal of rainforests
why is the amount of methane in the air increasing
larger amounts of cattle being farmed which release methane in their flatulence
why is the amount of water vapour in the air increasing
more water evaporating from oceans as the earths temp increases
what may happen if the earths temp increases
melting of polar ice caps which will lead to a rise in sea level and the flooding of low lying land
this will cause destruction of farm land animal habitats, homes and cause large scale migration of people
change in climates around the world ➡️some regions wil become warmer, colder, drier and wetter, drought could destroy vast regions of farmland across the globe leading to a world food shortage and mass starvation
what is potable water
water that is safe for drinking
what are the first 3 water treatment steps in order with explanations
screen - to remove large bits of solid waste eg branches,leaves
sand filters- remove smaller bits of solid waste eg suspended grit
sedimentation tank - water is left to settle ➡️ fine particles of solid fall to the bottom of the tank as sediment
what are the last 2 water treatment steps
further sand filters - remove finer solid particles
chlorine is added - doesnt purify but sterilises water
what process does water need to go through to remove dissolved substances
distilling
what did democritus suggest
all substances were made out of atoms
what did john dalton propose
-matter us composed of tiny particles called atoms
-atoms of a particular element are alike in size,shape and weight but differ from atoms of other elements
-during chemical changes, atoms of different elements unite forming molecules (compounds)
-during these chemical changes, atoms themselves dont change
-when atoms combine they do so in definite whole number ratios
what did jj thomson do
discovered electrons with cathode rays
what did james chadwick do
did experiments that confirmed the existence of the electron
what is the relative charge of a proton
+1
what is the relative charge of a neutron
0
what is the relative charge of an electron
-1
what is the relative mass of a proton
1
what is the relative mass of a neutron
1
