Answer:
Acid base indicators are weak and acids and bases, which are used to signify the end point of neutralization reaction. The type of indicator used for a neutralization reaction depends on the strength of the acid and the base, that are involved in the reaction. A good acid base indicator must have a good pH range and it must be able to produce specific and identifiable color in specific acid base medium.
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Two good properties of an indicator are as follows-
1) It should be specific- It means that the changes, which are measured by the indicator should be expressed in precise terms so that appropriate assessment could be made.
2) It should be time bound- This means that the measurable changes should arrive withing a particular time limit.
Example of indicator- Litmus is an acid base indicator that turns acidic solutions red and basic solutions into blue color.
Well you see each of the seeds have developed a special technique that allows their individual seeds to travel further and lower the probability of landing close to the tree and not getting the sunlight it needs
For the berries birds and various animals eat them carrying them away so hopefully they can get more sunlight
Helicopter seeds do the same thing except the sides themselves float away from the tree to get a further distance.
Finally the acorn seeds of the oak tree use the same concept of the berries. Various squirrels do eat these kinds of nuts and bury them in the ground in hopes of finding them later. But due to squirrels not remembering where they buried their acorn seeds the acorns are well away from the tree and start growing.
So you see all of these tree seeds are specially developed to help it get away from the trees. Especially so that they can grow in a much better environment than the one provided to them initially.
Collenchyma and Parenchyma because they are cellulose containing cells.
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1) The environment of nebulas attract the dust and gas together and forms the necessary components of a star.
2) It is created by comparing different stars by their luminosity and color.
The appropriate answer is c. a scientific journal. A scientific journal is a collection of papers based on topics in science that have been written by experts in their fields. Individuals with a masters or doctorate in various subject areas are published here.
From the list given this is the best second source for the research. Science fiction novels and not real and so would be unacceptable. Magazines and news papers reporting on scientific research most likely get information from scientific journals.