I made a mistake not 5a
its wrong link leave it
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Physics, Chemistry and Biology: Post your doubts here!
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its wrong link leave it
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ok mo prob
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Walaikum salamAssalam-o-Alaikum.
Post your Physics, Chemistry and Biology doubts in here and members, along with me will try there best to help you out.
please provide me the past papers from 1996 to 2000 (biology 0610)
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freeexampapers.com
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Chemistry problem.......
What is a mole and there is something that there is a certian amount of atoms in a mole no matter which element is it and how much space does 1 mole of any gas occupy??
What is a mole and there is something that there is a certian amount of atoms in a mole no matter which element is it and how much space does 1 mole of any gas occupy??
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Can any1 please let me know how can I get all past papers from 1996 to till date.
Also mention any software to download all these questions all together.
Also mention any software to download all these questions all together.
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A mole is defined as the number of atoms in exactly 12 grams of 12C (Carbon)
the second one is the Avogadro's number, which is 6*10^23
The third answer is 24dm^3
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freeexampapers.comCan any1 please let me know how can I get all past papers from 1996 to till date.
Also mention any software to download all these questions all together.
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URGENT BIOLOGY HELP NEEEEEEEDED!!! >.<
Okay, theres this question involving an investigation of storage time on seed germination. It says that old seeds tend to have low % of seed germination. I need to plan an experiment on this, and I have no idea how. It needs evidence too! and the likely source of error regarding this and how would I improve it for the better. INSTANT HELP NEEDED PLZ!
Need to submit this tomorrow! ugh.
Okay, theres this question involving an investigation of storage time on seed germination. It says that old seeds tend to have low % of seed germination. I need to plan an experiment on this, and I have no idea how. It needs evidence too! and the likely source of error regarding this and how would I improve it for the better. INSTANT HELP NEEDED PLZ!
Need to submit this tomorrow! ugh.
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The best way to find the effect of storage time on seed germination would be to gather a lot of fresh seeds, and put them into storage. Every year, you could randomly choose several seeds and plant them, and see what percentage will germinate. But to get a really good idea of germination, and to have good statistical results when comparing the germination rates, you would probably want a hundred or so seeds in each batch you tried to germinate. That means if you wanted to carry out the experiment for 25 years, you'd need a minimum of 25,000 seeds at 100 per year. Needless to say that would require some effort to get and store that many seeds, and a lot of time to get your results (not that it would require a lot of your time each year, just what it would take you to prepare the pots or soil outside, and the actual planting - then you'd just have to observe the pots/area to see when/if and seeds germinated; if you could attempt germination with just a moist paper towel, it would make things go even that much faster with less space needed!)
The drawback to an experiment of this sort is that you only get information based on the type of storage method that you used, for the species of plant whose seeds you used, and for the germination conditions that were used. If any variable was changed, your results might change, so the information is only good for a limited set of circumstances. Of course, you could collect 1,000 times more seeds, then set up seeds in different storage conditions (temperature, light, and humidity would be variables that could affect germination), and try using different germination situations (depth of planting, soil pH, soil type, amount of soil moisture, soil temperature). And if you were really ambitious, you could run the same experiment with several different species of plants.
Realistically, you wouldn't carry out this experiment for 25 years. For many species, the germination rate would drop off after just a few years. And for some seeds with a long period of seed dormancy, you might only try germinating the seeds every 5 years or so to check their viability.
Below are some websites & scientific papers related to seed viability & experiments. You might look at some of these for ideas on seeds to use and materials & methods.
(And of course, having evidence from the results of prior experiments done in peer-reviewed journals isn't a bad idea either!)
Source(s):
http://www.ipm.iastate.edu/ipm/hortnews/…
http://planet.botany.uwc.ac.za/nisl/Gwen…
http://www.ars.usda.gov/research/publica…
http://www.ars.usda.gov/research/publica…
http://www.kew.org/science-research-data…
The drawback to an experiment of this sort is that you only get information based on the type of storage method that you used, for the species of plant whose seeds you used, and for the germination conditions that were used. If any variable was changed, your results might change, so the information is only good for a limited set of circumstances. Of course, you could collect 1,000 times more seeds, then set up seeds in different storage conditions (temperature, light, and humidity would be variables that could affect germination), and try using different germination situations (depth of planting, soil pH, soil type, amount of soil moisture, soil temperature). And if you were really ambitious, you could run the same experiment with several different species of plants.
Realistically, you wouldn't carry out this experiment for 25 years. For many species, the germination rate would drop off after just a few years. And for some seeds with a long period of seed dormancy, you might only try germinating the seeds every 5 years or so to check their viability.
Below are some websites & scientific papers related to seed viability & experiments. You might look at some of these for ideas on seeds to use and materials & methods.
(And of course, having evidence from the results of prior experiments done in peer-reviewed journals isn't a bad idea either!)
Source(s):
http://www.ipm.iastate.edu/ipm/hortnews/…
http://planet.botany.uwc.ac.za/nisl/Gwen…
http://www.ars.usda.gov/research/publica…
http://www.ars.usda.gov/research/publica…
http://www.kew.org/science-research-data…
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100% copied and paste from my 'friends answer' on yahoo answer. Nice!
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The quality and quantity of food available worldwide has been improved by artificial
selection (selective breeding) and genetic engineering.
(d) Use a named example to outline how artificial selection is used to improve the quantity
or quality of food.
whats this question
pzl help
selection (selective breeding) and genetic engineering.
(d) Use a named example to outline how artificial selection is used to improve the quantity
or quality of food.
whats this question
pzl help
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lol
good u found outhey all , im having a hard time doing the chemistry past papers even though i have studied my chemistry revision guide to the fullest , but still chemistry is like japanese language to me so is there any technique that i can follow which can make me get an A ?
PLEASE HELP
PLEASE HELP
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Wa Alikum Assalam I have doubts in Mole Concepts (chem) can u plz help and giv some sources. Thank U
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i can help u in balancing equations if i try
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since they require one more electron to become stable they covalently bond with another of the same element Eg
chlorine has 7 electrons in the valence shell so it shares one more electron with another chlorine atom to form
a chlorine molecule which is diatomic. All gases except noble gases are diatomic and all halogens are diatomic . Hope u understood the concept.....
Thank you!since they require one more electron to become stable they covalently bond with another of the same element Eg
chlorine has 7 electrons in the valence shell so it shares one more electron with another chlorine atom to form
a chlorine molecule which is diatomic. All gases except noble gases are diatomic and all halogens are diatomic . Hope u understood the concept.....