SLIDESMANIA.COM Materials and cycles on Earth ATOMS SLIDESMANIA.COM SLIDESMANIA.COM SLIDESMANIA.COM SLIDESMANIA.COM BUILD AN ATOM LINK https://phet.colorado.edu/sims/html/build-an-atom/l atest/build-an-atom_en.html SLIDESMANIA.COM Characteristics of an atom 1. Proton and neutrons are closely group to ether 2. Proton + neutron = nucleus 3. Most of the mass of an atom comes from proton and neutron (nucleus) , electrons have almost no mass. 4. Positivel char ed particles = protons Negativel char ed particles = electrons Neutral particles = neutrons SLIDESMANIA.COM 5. In a stable atom no. of protons = no. of electrons 6. There is lot of empty s ace etween arts of an atom HISTORY OF AN ATOM SLIDESMANIA.COM J.J THOMAS MODEL OF AN ATOM J.J. Thomson's experiments with cathode ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons. SLIDESMANIA.COM LINK https://www.youtube.com/watch?v=X2uvuSThtuI SLIDESMANIA.COM RUTHERFORD GOLD FOIL EXPERIMENT SLIDESMANIA.COM ● Rutherford used a old foil to bombard alpha articles (helium nuclei) and observed the scattered particles. ● He found that most of the alpha particles passed straight through the foil, but a few were deflected. He also found that the amount of deflection was roportional to the angle at which the alpha particle was scattered. ● This experiment demonstrated that the alpha particles were small and had a positive charge. It also showed that the nucleus was concentrated in the center of the atom and that the electrons were spread out around it. PURE SUBSTANCES SLIDESMANIA.COM GOLD SLIDESMANIA.COM SILVER Silver is marked with the number of parts per thousand that are silver Eg . 925 mar ed silver 925 / 1000 x 100 = 92.5% pure silver SLIDESMANIA.COM DIAMONDS Diamonds are made up of onl t e of element “car on” To give color to the diamond few car on atoms are re laced b another element SLIDESMANIA.COM Carbon replaced by Color of diamond Nitrogen yellow Boron Blue Nitrogen , nickel and hydrogen Green SEA WATER Salinity is the concentration of dissolved inor anic salts in seawater ( rams of salt per ilogram sea water, or parts per thousand, and given the symbol ‰). 68% sodium chloride = 68/100 35g of salts in the sea water Amount of sodium chloride = 68/100 x 35 = 23.8g In 1000g of seawater SLIDESMANIA.COM Weather and climate SLIDESMANIA.COM Glacial and interglacial period Glacial period Interglacial period marked by colder temperatures and glacier advances. periods of warmer climate between glacial periods. SLIDESMANIA.COM Ice spread south No permanent ice from north pole and close to the North north from south and South pole pole Ice age cycle LINK https://www.youtube.com/watch?v=I4EZCy14te0 SLIDESMANIA.COM Evidence for Ice age 1. Boulders in strange position The presence of hu e boulders in strange osition explanation is given b scientists as - SLIDESMANIA.COM The were carried by glaciers moving slowl downhill and when the lacier melt the are le behind 2. Pollen evidence Peat o - Peat forms when lant material does not full deca in acidic and anaero ic conditions. It is composed mainl of wetland vegetation: princi all bog lants Scientist take sample of peat bog using Auger to remove a core of the eat o . SLIDESMANIA.COM The collect pollen from different art of the core and identif the lant it elongs to. Accordin to the climate the plant grows in we work out the climate in that time eriod. SLIDESMANIA.COM The atmosphere SLIDESMANIA.COM 4600 million ears ago 4000 million ears ago ● Earth was created ● The Earth was ver hot and contained around 95% of CO2. ike venus has it toda . ● There was a lot of volcanic activit . ● The gases from the volcanic eruption formed the early atmosphere. ● Water vapour which was roduced b the volcanoes cooled the Earth. ● The water va our condensed and fell as rain forming the first la e and oceans. Changes to the atmosphere 3500 million ears ago 200 million ears ago ● Micro-organisms develo ed on Earth ● The lived in ocean and used CO2 in atmosphere to make food. ● Plants developed and used CO2 to ma e food on land. ● Ver little CO2 le ● Most of the car on used to ma e the chemicals. CO2 + 2O Glucose + O2 SLIDESMANIA.COM ● Ox en level rises and enough to combine with iron to form iron oxide. Carbon ● When organisms die the car on is released ack in the atmosphere. ● Some or anisms do not rot and the carbon is loc ed up in them forming fossil fuels such as coal and oil. ● 600-400 million ears ago the animals that have shells (made up of calcium car onate CaCO3) die and fall at the bottom of the ocean as sediment, the man layers of the shells ressing down on each other form roc s such as limestone. SLIDESMANIA.COM THANK YOU SLIDESMANIA.COM Nothing is indifferent, nothin is powerless in the universe; an atom might destro ever thing, an atom might save ever thing! -Gerard De Nerval
