- Calculate stream gradient (rise/run) if the elevation of a stream changes from 3000 ft MSL to 1000 ft MSL over a distance of 2 miles.
- Which of the following statements define environmental chemistry?
a) study of chemical reactions that occur in water, air, land, biological habitats, and human activities
b) study of chemical reactions that occur in water, air, land, and biological habitats only
c) study of chemical reactions that occur in water, air, and land only
d) None of the above
The Correct Answer and Explanation is :
1. Stream Gradient Calculation:
To calculate the stream gradient (rise/run), we use the formula: Gradient=Rise (elevation change)Run (distance)\text{Gradient} = \frac{\text{Rise (elevation change)}}{\text{Run (distance)}}
- Rise (elevation change): 3000 ft MSL – 1000 ft MSL = 2000 ft
- Run (distance): 2 miles (convert to feet: 1 mile = 5280 feet)
So, the distance is: Run=2×5280=10560 ft\text{Run} = 2 \times 5280 = 10560 \text{ ft}
Now, we can calculate the gradient: Gradient=2000 ft10560 ft≈0.189 ft/ft\text{Gradient} = \frac{2000 \text{ ft}}{10560 \text{ ft}} \approx 0.189 \text{ ft/ft}
Thus, the stream gradient is approximately 0.189 ft/ft.
2. Which of the following statements define environmental chemistry?
The correct answer is:
a) study of chemical reactions that occur in water, air, land, biological habitats, and human activities
Explanation:
Environmental chemistry is a field that focuses on understanding the chemical processes that take place in the environment. It involves studying the interactions of chemicals in natural and man-made systems, including the air, water, land, biological habitats, and the influence of human activities.
- Water: Chemicals in water can undergo various reactions, including contamination by pollutants and natural processes like nutrient cycling. Environmental chemistry examines how these chemicals affect water quality and ecosystems.
- Air: Atmospheric chemistry studies chemical reactions in the air, such as the formation of pollutants like ozone and particulate matter, which can affect climate and air quality.
- Land: This includes the study of soil chemistry, where chemicals from fertilizers, pesticides, and other contaminants interact with soil and the organisms that live in it.
- Biological Habitats: This aspect focuses on how chemicals influence living organisms and ecosystems, including nutrient cycles, the impact of pollution on wildlife, and the biochemistry of habitats.
- Human Activities: Human impact is a major part of environmental chemistry, as industrial processes, agriculture, and waste management introduce chemicals into the environment, potentially causing harm or leading to environmental degradation.
In summary, environmental chemistry looks at how chemical reactions in different environmental media (water, air, land, biological systems) are influenced by both natural processes and human activities. Therefore, option (a) is the most comprehensive and correct definition.
Option (b) is incorrect because it excludes human activities, which are a major factor in environmental chemistry. Option (c) is incorrect because it doesn’t mention biological habitats, which are crucial in understanding the effects of chemicals. Option (d) is incorrect as option (a) is the correct definition.