<u>Answer:
</u>
When the outer electron shell is full in an element, this creates a Noble gas.
<u>Explanation</u>:
Noble gases are the elements that belong to group 18 in the periodic table. Noble gases are also called as inert gases. The outermost shell of the noble gases are fully filled by electrons. Due to this the noble gases don’t react with any other elements and remain isolated.
There are 6 noble gases in the periodic table. They are helium (He), Argon (Ar), Neon (Ne) Krypton (Kr), Radon (Rn) and Xenon (Xe). Noble gases conduct electricity. They are fluorescent, odorless and colorless. Noble gases are used a maintain stable elements in a constant and safe environment.
The right answer is D.
The absorption of molecules at the level of the skin is carried out by passive diffusion for the molecules of low molecular weight (lower than 400 Da), the skin being covered with a lipoprotein film rich in water by its stratum corneum, rendering it little-permeable.
This absorption may be variable according to factors related to the skin such as stratum corneum's thickness, the state of hydration, the presence of cutaneous lesions or individual variations.
External factors may also modulate percutaneous absorption such as contact time, iontophoresis or the presence of specific adjuvants.
Answer:
the answer would be the first one which is sexual reproduction
B) they work independently of one other
