We have to know how urbanization causes pollution.
The reason is: People in urban areas consume more energy, food, and water.
Urbanisation is one of the major problem towards pollution. The smoke from automobiles, factories and power generators make air unhealthy. Also chemical spills and other toxic gases contaminate in air.
The mixing of toxins in the soil is polluting soil which disturbs eco-system.
The high density population in urban area consume more energy , food and water which causes pollution.
Answer:
The average atomic mass is closer to Si- 28 because this isotope is present in more percentage in the sample.
Explanation:
Given data:
Atomic mass of silicon= ?
Percent abundance of Si-28 = 92.21%
Atomic mass of Si-28 = 27.98 amu
Percent abundance of Si-29 = 4.70%
Atomic mass of Si-29 = 28.98 amu
Percent abundance of Si-30 = 3.09%
Atomic mass of Si-30 = 29.97 amu
Solution:
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)+(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass = (92.21×27.98)+(4.70×28.98)+(3.09×29.97) /100
Average atomic mass = 2580.04 +136.21+92.61 / 100
Average atomic mass = 2808.86 / 100
Average atomic mass = 28.08amu.
The average atomic mass is closer to Si- 28 because this isotope is present in more percentage in the sample.
The most accurate way to measure a dry ingredient like flour, sugar or chocolate chips is in terms of its weight, which is measured in regular ounces.
Answer: It showed that all atoms contain electrons.
Explanation:
- J.J. Thomson's experiments inside a cathode ray tube in the presence of an electric field showed that all atoms contain tiny negatively charged subatomic particles "electrons".
- Also, Thomson's plum pudding model of the atom had negatively-charged electrons embedded within a positively-charged "soup."
- Furthermore, Rutherford's gold foil experiment showed that the atom is mostly empty space with a tiny positively-charged nucleus.
- Then, Rutherford proposed the nuclear model of the atom based on these results.
Answer:
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