Wednesday, May 21, 2008
Tues-Day 2
Bio- we discussed some of the ways that humans impact the environment:
by over-hunting and over-fishing, humans have caused the extinction of various species: the dodo-bird, the QUAGGA, one of Africa's most famous extinct animals, was a subspecies of the plains zebra, which was once found in great numbers in South Africa's Cape Province and the southern part of the Orange Free State. It was distinguished from other zebras by having the usual vivid marks on the front part of the body only. The Tasmanian Tiger was hunted to extinction in 1936. The sea cow grew up to 7.9 meters (25.9 ft) long and weighed up to three tons, much larger than the manatee but is now extinct.
By burning fossil fuels, carbon dioxide concentration in the atmosphere increases and can contribute to the greenhouse effect. Also oxides of sulfur and nitrogen, from burning coal and other fuels, can react with water in the air to form acids, which produce acid rain that changes the abiotic factor, pH, of aquatic biomes. This can upset a stable ecosystem.
Chem 7/8- we learned the six-step process for balancing a redox reaction via the "oxidation number" method. Some of these balancing problems are harder than others due to the following factors: elements that have subscripts e.g. Cr2O7 2- must have their mass balanced BEFORE the charge is balanced in a half-reaction; also, the oxidation number assigned to an element with a subscript means that EACH of the atoms of that element have the SAME oxidation number in a given compound e.g. in H2O2, EACH H is +1 and EACH O is -1.
We then finished our discussion of the acid-base titration lab.
Chem 9- we learned the six-step process for balancing a redox reaction via the "oxidation number" method. Some of these balancing problems are harder than others due to the following factors: elements that have subscripts e.g. Cr2O7 2- must have their mass balanced BEFORE the charge is balanced in a half-reaction; also, the oxidation number assigned to an element with a subscript means that EACH of the atoms of that element have the SAME oxidation number in a given compound e.g. in H2O2, EACH H is +1 and EACH O is -1.
by over-hunting and over-fishing, humans have caused the extinction of various species: the dodo-bird, the QUAGGA, one of Africa's most famous extinct animals, was a subspecies of the plains zebra, which was once found in great numbers in South Africa's Cape Province and the southern part of the Orange Free State. It was distinguished from other zebras by having the usual vivid marks on the front part of the body only. The Tasmanian Tiger was hunted to extinction in 1936. The sea cow grew up to 7.9 meters (25.9 ft) long and weighed up to three tons, much larger than the manatee but is now extinct.
By burning fossil fuels, carbon dioxide concentration in the atmosphere increases and can contribute to the greenhouse effect. Also oxides of sulfur and nitrogen, from burning coal and other fuels, can react with water in the air to form acids, which produce acid rain that changes the abiotic factor, pH, of aquatic biomes. This can upset a stable ecosystem.
Chem 7/8- we learned the six-step process for balancing a redox reaction via the "oxidation number" method. Some of these balancing problems are harder than others due to the following factors: elements that have subscripts e.g. Cr2O7 2- must have their mass balanced BEFORE the charge is balanced in a half-reaction; also, the oxidation number assigned to an element with a subscript means that EACH of the atoms of that element have the SAME oxidation number in a given compound e.g. in H2O2, EACH H is +1 and EACH O is -1.
We then finished our discussion of the acid-base titration lab.
Chem 9- we learned the six-step process for balancing a redox reaction via the "oxidation number" method. Some of these balancing problems are harder than others due to the following factors: elements that have subscripts e.g. Cr2O7 2- must have their mass balanced BEFORE the charge is balanced in a half-reaction; also, the oxidation number assigned to an element with a subscript means that EACH of the atoms of that element have the SAME oxidation number in a given compound e.g. in H2O2, EACH H is +1 and EACH O is -1.
# posted by C @ 12:30 PM 
