Answer:
I need help for this question
Answer:
A. there is an isotope of lanthanum with an atomic mass of 138.9
Explanation:
By knowing the different atomic masses of both Lanthanum atoms, we can not tell anything about their occurence in nature. Therefore, all the last three options are incorrect. Because, the atomic mass does not tell anything about the availability or natural abundance of an element.
Now, the isotopes of an element are those elements, which have same number of electrons and protons as the original element, but different number of neutrons. Therefore, they have same atomic number but, different atomic weight or atomic masses.
Hence, by looking at an elements having same atomic number, but different atomic masses, we can identify them as isotopes.
Thus, the correct option is:
<u>A. there is an isotope of lanthanum with an atomic mass of 138.9.</u>
The answer is C. <span>The wind removes surface particles, resulting in lower land surface.
Deflation is the process of lifting and moving of tiny particles of soil or sand, brought about by the wind. It can also be associated with soil erosion. This is a common phenomenon in deserts and sand dune areas near the coast.</span>
Answer:
it is b
Explanation:
A drainage basin is any area of land where precipitation collects and drains off into a common outlet, such as into a river, bay, or other body of water
Answer:
B. Thicker layer of blubber
Explanation:
For the leopard seals to survives this harsh environment, it must have a thicker layer of blubber
Blubber is a thick layer of fat. It is called the adipose tissues and found in most marine organisms.
- This layer helps in insulating the body against heat loss.
- By so doing, the animal is able to conserve internal heat.
- They have low thermal conductivity and do not easily lose heat or gain heat as such.
