Some hydrocarbons are regarded as unsaturated because they contain double or triple bonds between adjacent carbon atoms. 
<h3>What are hydrocarbons?</h3>
Hydrocarbons are any organic compounds that contain hydrogen and carbon in its structure. 
Hydrocarbons can be grouped into the following based on whether they contain single or double bonds:
- Saturated hydrocarbons - contain only single bonds e.g. alkanes
- Unsaturated hydrocarbons - contain double and triple bonds e.g. alkenes
Therefore, it can be said that some hydrocarbons are regarded as unsaturated because they contain double or triple bonds between adjacent carbon atoms. 
Learn more about hydrocarbons at: brainly.com/question/17578846
 
        
             
        
        
        
Answer:
increasing rainfall. hope it help
 
        
             
        
        
        
Answer:
The number of electrons in the outermost shell of an atom determines its reactivity. Noble gases have low reactivity because they have full electron shells. Halogens are highly reactive because they readily gain an electron to fill their outermost shell.
Explanation:
I hope this helped!
 
        
             
        
        
        
Answer:
sp³
Explanation:
Number of hybrid orbitals = ( V + S - C + A ) / 2
Where 
H is the number of hybrid orbitals
V is the valence electrons of the central atom = 5
S is the number of single valency atoms = 4
C is the number of cations = 1
A is the number of anions = 0
For PCl₄⁺
Applying the values, we get:
H = ( 5+4-1+0) / 2
= 4 
<u>This corresponds to sp³ hybridization.</u>
 
        
                    
             
        
        
        
Here is the complete question.
Benzalkonium Chloride Solution ------------> 250ml
Make solution such that when 10ml is diluted to a total volume of 1 liter a 1:200 is produced.
Sig: Dilute 10ml to a liter and apply to affected area twice daily
How many milliliters of a 17% benzalkonium chloride stock solution would be needed to prepare a liter of a 1:200 solution of benzalkonium chloride?
(A) 1700 mL
(B) 29.4 mL
(C) 17 mL
(D) 294 mL
Answer:
(B) 29.4 mL
Explanation:
1 L  =   1000 mL 
1:200 solution implies the  in 200 mL solution.
 in 200 mL solution.
200 mL of solution = 1g of Benzalkonium chloride
1000 mL will be 
200mL × 1g = 1000 mL × x(g)
x(g) = 
x(g) = 0.2 g
That is to say, 0.2 g of benzalkonium chloride in 1000mL of diluted solution of 1;200 is also the amount in 10mL of the stock solution to be prepared.
∴ 
y(g) = 
y(g) = 5g of benzalkonium chloride.
Now, at 17%  concentrate contains 17g/100ml:
 concentrate contains 17g/100ml:
∴  the number of milliliters of a 17% benzalkonium chloride stock solution that is needed to prepare a liter of a 1:200 solution of benzalkonium chloride will be;
= 
z(mL) = 
z(mL) = 29.41176 mL
≅ 29.4 mL
Therefore, there are 29.4 mL of a 17% benzalkonium chloride stock solution that is required to prepare a liter of a 1:200 solution of benzalkonium chloride