The electron is the only subatomic particle that has a negative charge
Answer:
D. Waste management issues
Explanation:
Answer A: The five major types of pollution - water pollution, air pollution, land pollution, light pollution, noise pollution - have negative effects on the environment, on human health, and our planet as a whole.
Answer B: Urban Heat Island (UHI) is an urban area that is significantly warmer than its surrounding rural areas due to human activities. UHI decreases air quality.
Answer C: The increased use of surrounding land is the main cause of biodiversity loss.
Answer D: Any field of environmental management help people to solve pollution problems. So, D is the correct answer.
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Answer:
b. The transmittance of the cuvette must be measured in the same place each time.
Explanation:
When using a spectrophotometer, light passes not only through the liquid sample, it also passes through the cuvette. This means that each time a reading is made, you not only measure the transmittance/absorbance of the sample, <u>but of the cuvette as well</u>.
For this reason it's important that the reading of the cuvette's absorbance remains the same through all the process, so the answer is b), because different faces of the cuvette may have different absorbances.
Answer:
2.4mol
Explanation:
In order to calculate numbers of moles we have to divide the given mass by the molar mass of the substance (ibuprofen) n= m/M
To calculate the molar mass we have
C13= 12*13= 156
H18= 1*18=18
O2= 16*2 =32
Molar mass M = 153+18+32= 206g
Given the mass m= 250g per tablet
Hence number of moles in one tablet is n= 250/206= 1.2 mol
Therefore the total number of ibuprofen you took is 1.2*2 (for the two tablets) = 2.4 moles
It is one or more cells because there are organisms that are only 1 cell, such as some bacteria.