Answer:
d. white blood cells
Explanation:
It is the white blood cells that have the least tendency to cross the blood- brain barrier.
Blood- brain barrier is psychological barrier and restricts substances that circulate into the blood from crossing over the central nervous system.
Water, glucose as well as sodium ions can easily cross the barrier. As these are good for body supply energy to the brain.
Answer:- Frequency is
.
Solution:- frequency and wavelength are inversely proportional to each other and the equation used is:
![\nu =\frac{c}{\lambda }](https://tex.z-dn.net/?f=%5Cnu%20%3D%5Cfrac%7Bc%7D%7B%5Clambda%20%7D)
where,
is frequency, c is speed of light and
is the wavelength.
Speed of light is
.
We need to convert the wavelength from nm to m.
(
)
![550nm(\frac{10^-^9m}{1nm})](https://tex.z-dn.net/?f=550nm%28%5Cfrac%7B10%5E-%5E9m%7D%7B1nm%7D%29)
= ![5.5*10^-^7m](https://tex.z-dn.net/?f=5.5%2A10%5E-%5E7m)
Now, let's plug in the values in the equation to calculate the frequency:
![\nu =\frac{3.0*10^8m.s^-^1}{5.5*10^-^7m}](https://tex.z-dn.net/?f=%5Cnu%20%3D%5Cfrac%7B3.0%2A10%5E8m.s%5E-%5E1%7D%7B5.5%2A10%5E-%5E7m%7D)
=
or ![5.4*10^1^4Hz](https://tex.z-dn.net/?f=5.4%2A10%5E1%5E4Hz)
since, ![1s^-^1=1Hz](https://tex.z-dn.net/?f=1s%5E-%5E1%3D1Hz)
So, the frequency of the green light photon is
.
Answer:
c. form trihalomethanes with organic compounds
Explanation:
Chloramines are compounds which are the derivatives of organic amine and ammonia. The N-H bonds in these compounds have been replaced by the N-Cl bonds. There are mainly two types of chloramines and they are inorganic chloramines and organic chloramines. Generally, chloramines contain chlorine, can be used to sanitize and disinfect, are safer than free chlorine, and can also be used to treat wounds and skin surfaces. Therefore, the correct option is (c) because chloramines do not form trihalomethanes with organic compounds.
Answer:
Lead I think is one I'm not completely sure but I know they're similar in some ways