The first pesticides relied on natural chemicals, such as those taken from chrysanthemum flowers is true
The statement which is true is
metals lose electrons to become cations
<u><em>Explanation</em></u>
- metals tends to loss electrons to attain noble gas electrons configuration.
- When metal loses electrons they form a positive charged ions.
- The positively charged ion is known as cations.
- for example sodium metal (Na) loses 1 electron to form a cation with a charge of positive 1 ( Na^+)
Explanation:
I hope you interested about the chemical what they add in tea
Answer:
particles larger than 5 microns are normally expelled. -particles smaller than 5 microns may enter into alveolar sacs. ... -chemical can penetrate skin and go into bloodstream.
Explanation:
Answer:
75 mg
Explanation:
We can write the extraction formula as
x = m/[1 + (1/K)(Vaq/Vo)], where
x = mass extracted
m = total mass of solute
K = distribution coefficient
Vo = volume of organic layer
Vaq = volume of aqueous layer
Data:
m = 75 mg
K = 1.8
Vo = 0.90 mL
Vaq = 1.00 mL
Calculations:
For each extraction,
1 + (1/K)(Vaq/Vo) = 1 + (1/1.8)(1.00/0.90) = 1 + 0.62 = 1.62
x = m/1.62 = 0.618m
So, 61.8 % of the solute is extracted in each step.
In other words, 38.2 % of the solute remains.
Let r = the amount remaining after n extractions. Then
r = m(0.382)^n.
If n = 7,
r = 75(0.382)^7 = 75 × 0.001 18 = 0.088 mg
m = 75 - 0.088 = 75 mg
After seven extractions, 75 mg (99.999 %) of the solute will be extracted.
