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.
i believe it would be B '' tetrahedral compound ''
Answer:
Solids, liquids, and gases are made of tiny particles called atoms and molecules. In a solid, the particles are very attracted to each other. They are close together and vibrate in position but don't move past one another. In a liquid, the particles are attracted to each other but not as much as they are in a solid.
Answer:
Two
Explanation:
Elements in group 16 wants to bond with elements in group IIA, the group of alkaline earth metals.
- The bonding will make it easier for them complete their octet.
- Elements in group 16 has 6 valence electrons.
- To have a complete octet, they require 2 more electrons.
- Group II elements are willing donors as they are metals.
- For Group II elements to fill their octets, they must lose two electrons.
- So the willingness of group II elements to lose two electrons and the readiness for group 16 elements to gain the electrons makes the desire one another.
W=(m'/m)·100%
m'=37.2 g
m=48.5 g
w=(37.2/48.5)·100%=76.7%
