<span>The amount of dissolved salt in the liquid sample is measured and reported as salinity. The salinity is usually measured in parts per thousand (ppt). The salinity of ocean averages 35 ppt while that of the river averages 0.5 ppt or less. In other terms, the word salinity is the saltiness. </span>
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:
Metallic structure
Explanation:
They have a high melting point due to the strong forces of attraction between the positive ions (cations) and the delocalised electrons. Moreover, they conduct electricity due to the sea of delocalised electrons.
<em>[Extra: It could be an ionic compound since they also have a high melting point, however they only conduct electricity in liquid or aqeouus state.]</em>
Answer:
false
Explanation:
Atoms of the same element that differ in their numbers of neutrons are called isotopes. Many isotopes occur naturally. ... Different isotopes of an element generally have the same physical and chemical properties because they have the same numbers of protons and elec