A. density
<span>Reaction rate increases with concentration.</span>
<span>Hydrogen bonds are
approximately 5% of the bond strength of covalent bonds, for example (C-C or C-H
bonds).
Hydrogen bonds strength in water is approximately 20
kJ/mol, strenght of carbon-carbon bond is approximately 350 kJ/mol
and strengh of carbon-hydrogen bond is approximately 340 kJ/mol.
20 kJ/350 kJ = 0,057 = 5,7 %.</span>
Intensity has no affect on whether or not the photoelectric effect occurs. The determining property is frequency and since frequency and wavelength are inversely proportional, wavelength matters as well. If a frequency of light can't cause the photoelectric effect to happen, no matter what the intensity is, the light can't make it happen.
I hope this helps. Let me know in the comments if anything is unclear.
Adults have stem cells because they are needed to repair certain tissues in the body such as in the muscles, bone marrow, skin, teeth, heart, and liver, to name a few. Thus, they can develop into many different cell types and function to replace older and damaged tissues.
Answer:
SN2
Explanation:
The first step of ether cleavage is the protonation of the ether since ROH is a better leaving group than RO-.
The second step of the reaction may proceed by either SN1 or SN2 mechanism depending on the structure of the ether. Methyl and primary ethers react with HI by SN2 mechanism while tertiary ethers react with HI by SN1 mechanism. Secondary ethers react with HI by a mixture of both mechanisms.
Dipentyl ether is a primary ether hence when treated with HI, the reaction with HI proceeds by SN2 mechanism as explained above.
