C
The elements are Lithium and Beryllium— just look at the mass number on the periodic table
Adaptation actually and also following control measures on how to avoid it from happening
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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Hope this answer can help you. Have a nice day!
1 property
2 procedure
Results
The question is incomplete, complete question is :
Determine the pH of an HF solution of each of the following concentrations. In which cases can you not make the simplifying assumption that x is small? (
for HF is
.)
[HF] = 0.280 M
Express your answer to two decimal places.
Answer:
The pH of an 0.280 M HF solution is 1.87.
Explanation:3
Initial concentration if HF = c = 0.280 M
Dissociation constant of the HF = 

Initially
c 0 0
At equilibrium :
(c-x) x x
The expression of disassociation constant is given as:
![K_a=\frac{[H^+][F^-]}{[HF]}](https://tex.z-dn.net/?f=K_a%3D%5Cfrac%7B%5BH%5E%2B%5D%5BF%5E-%5D%7D%7B%5BHF%5D%7D)


Solving for x, we get:
x = 0.01346 M
So, the concentration of hydrogen ion at equilibrium is :
![[H^+]=x=0.01346 M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3Dx%3D0.01346%20M)
The pH of the solution is ;
![pH=-\log[H^+]=-\log[0.01346 M]=1.87](https://tex.z-dn.net/?f=pH%3D-%5Clog%5BH%5E%2B%5D%3D-%5Clog%5B0.01346%20M%5D%3D1.87)
The pH of an 0.280 M HF solution is 1.87.