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Plant Sciences, Zoology & Evolution / How much sulphur is toxic to crustaceans?
« on: 02/11/2018 01:36:08 »
How much sulphur can crustacean (yabbies, daphnias) take before mortality? Just need a general amount.
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Chemistry / What are the main properties of a polymer?
« on: 09/08/2018 07:11:16 »
what are the main properties of a organic and inorganic polymer? how does the primary, secondary and tertiary affect a polymer's properties?
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The Environment / What is biomass and productivity of grassland plants?
« on: 06/08/2018 02:25:40 »
What is biomass and productivity of Australian grassland plants/animals?
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Chemistry / Re: How can polymers be strengthened?
« on: 05/08/2018 11:30:06 »Is this homework by any chance?
topic for organic chem that is recommended to be revised not assigned just looking at my own will cause im a geek
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Chemistry / How can polymers be strengthened?
« on: 05/08/2018 09:12:45 »
How can changing secondary and tertiary structures of polymers affect the strength of thechain?
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Famous Scientists, Doctors and Inventors / Who and How did scientists theorise the plate tectonic movement?
« on: 05/08/2018 08:45:41 »
how did scientists create and develop these plate tectonic force theories? what evidence did they actually gather to lead each force? from what i know these theories have been constantly developed by other scientists, is this also true?
ridge push
slab pull
mantle convection
trench suction
ridge push
slab pull
mantle convection
trench suction
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The Environment / Re: what is the food web and trophic level of a Australian grassland?
« on: 05/08/2018 08:41:33 »The grassland is a primary producer - it captures the sunlight and uses the energy to drive photosynthesis and the production of plant biomass that the primary consumers eat. The food web is going to be very variable depending upon what lives on that land, and which bit of Australia you are considering....
Looking into south east side of australia (canberra), if you want a specific grassland heres one
https://www.environment.act.gov.au/parks-conservation/parks-and-reserves/find-a-park/canberra-nature-park/mulanggari-grassland-nature-reserve
the usual animals live here like kangaroo, snakes, lizards, possums, etc.
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The Environment / what is the food web and trophic level of a Australian grassland?
« on: 04/08/2018 04:57:11 »
what is the food web and trophic level of a Australian grassland?
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Geology, Palaeontology & Archaeology / how do the driving forces move plate tectonics?
« on: 02/08/2018 01:05:24 »
How does each driving force of plate tectonics work?
Ridge push,
Slab pull,
Slab suction,
Mantle convection.
Does ridge pushing and slab pulling happen because of mantle convection? Also which is the most accurate explanation out of the 4?
Ridge push,
Slab pull,
Slab suction,
Mantle convection.
Does ridge pushing and slab pulling happen because of mantle convection? Also which is the most accurate explanation out of the 4?
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The Environment / How do grassland ecosystem differ around the world?
« on: 27/07/2018 02:58:31 »
How does grassland ecosystem differ around the world? So far I've looked at different animals, e.g: in African grasslands, its full of lions, elephant, rhino's, etc whereas Australian grasslands consist of kangaroo's, wallabies, etc.
Does vegetation of grasslands differ around the world as well such as species of grasses? If so what kinds?
Another factor I looked at was how different countries grassland consist of different climate is this true?
Does vegetation of grasslands differ around the world as well such as species of grasses? If so what kinds?
Another factor I looked at was how different countries grassland consist of different climate is this true?
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The Environment / How can we prove rising sea levels are the consequence of global warming?
« on: 14/05/2018 00:26:15 »
What are some ways to prove that global warming does affect rising sea levels other than thermal expansion and metling of ice caps?
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Chemistry / Change in base wine chemical properties when it undergoes carbonation?
« on: 08/05/2018 11:49:52 »
What changes happen to the chemical properties of base wine if it goes under carbonation? WIll acidity, so2 levels, etc decrease? if so why?
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Chemistry / What is the redox reaction taking place in the ripper method between SO2 and I?
« on: 26/04/2018 12:03:22 »
What is the redox reaction occuring in the ripper titration method (wine SO2 determination), between SO2 and I2 and the use of starch indicator. How does this method determine the amount of SO2 both free and bound? What would the half reactions be and what is oxidised and reduced.
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Chemistry / How to calculate pH from kB?
« on: 26/03/2018 11:17:20 »
What is the pH of a 0.15 M solution of weak acid ammonium bromide? The Kb value for ammonia is 1.8 × 10^–5
I keep getting:
x=√(1.8*10^-5)(0.15)
x= 5.1*10^-3
-log(5.1*10^-3)
=pOH = 2.79
14-2.79
pH=11.71
I keep getting:
x=√(1.8*10^-5)(0.15)
x= 5.1*10^-3
-log(5.1*10^-3)
=pOH = 2.79
14-2.79
pH=11.71
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Physiology & Medicine / Re: How does the optic nerve and occipital lobe relate to reaction time?
« on: 18/03/2018 09:58:34 »
How does reaction time depend on photoreceptors?
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Physiology & Medicine / Re: How does the optic nerve and occipital lobe relate to reaction time?
« on: 17/03/2018 10:31:44 »Do you mean the rate of information transmission along the nerve and then the rate of processing through the visual cortex?
Yes, how does the two relate to the time of human reaction?
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Physiology & Medicine / How does the optic nerve and occipital lobe relate to reaction time?
« on: 16/03/2018 10:43:19 »
How do the optic nerve and occipital lobe relate to the reaction time of a human?
Also, are there any type of physiological differences between photoreceptors (rods and cones) that could result in a different reaction time?
Also, are there any type of physiological differences between photoreceptors (rods and cones) that could result in a different reaction time?
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Science Experiments / How to improve radioactivity dice experiment?
« on: 07/03/2018 03:42:38 »
Any suggestions to improve radioactivity dice experiment?
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Physics, Astronomy & Cosmology / Re: How do you use decay constant formula to find decay in excel?
« on: 04/03/2018 11:43:22 »Define your decay constant L
Put your starting number into a cell, say B2. I always start with B2 to give me space for annotations.
In B3 write =B2*exp(-L)
Now use autofill to give values for B4.....BN where N is as large as you like.
You can calculate the half life t½ = ln2/L = 0.693/L and compare it with the graphical value.
The half-life or decay constant you use depends on how you want to reject the dice, usually either 1/6 per throw or 1/2 per throw. 1/6 will give you a smoother curve and a better fit between experiment and calculation - just like real life where measuring short halflives is much more difficult!.
Using decay formula Nt = N0e-λt, I replaced decay constant with 0.166 (dice 1/6 chance) then compared to the results of the formula N=1000(1-1/6)^t (time). Would this be a fair comparison of expected dice vs expect dice decay results?
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Physics, Astronomy & Cosmology / Can carbon-14 decay and dice experiment decay results be compared?
« on: 03/03/2018 12:48:21 »
Say for the the number of parent isotopes left from the dice experiment at the 2nd time interval was 716 and the carbon 14 decay at the 2nd time interval is 924. Is it a valid comparison or because there isnt a decay constant for the dice experiment you cant compare the two? If you made the decay constant for the dice experiment 1/6 (0.166) and calculated the results would you be able to compare the dice results and carbon14 decay?