Hello! I believe you are asking what a Cell wall Is.
Answer:
<em> A rigid layer of nonliving material that surrounds the cells of plants and some other organisms.</em>
Explanation:
A cell wall is<u><em> a sturdy outer layer of protection of the plant cell. It protects the cell membrane and other organelles from the environment, bacteria, and viruses</em></u>. It is composed of cellulose, lignin, and suberin interspersed with carbohydrates and proteins.
Hope this Helps!
After one half life, 188mg
46.9 mg of Ba-142
After 5 half lives
After 106 minutes
20 half lives , only 0.000358 mg remains
Hope this helps
Answer:Use the K L M N shell orbit
Explanation: Valence electrons are those electrons on the outermost shell of an atomic nucleus.
The K L M N electron shell is named by a spectroscopist called Charles G. Barkla, who discovered the A X-rays ( high energy rays) and the B X-rays ( low energy rays), he later renamed the A X-rays K X-rays which is the Energy level orbit, and the B X-rays was also renamed to be the L M N and so on.
PLEASE SEE PICTURE ATTACHED
THE PICTURE SHOWS HOW TO DETERMINE VALENCE ELECTRON USING THE As AND B's WHICH ARE THE K L M N SHELL ORBIT, USING SILICON AS AN EXAMPLE.
The maximum number of electron in the K orbit is 2
The maximum number of electron in the L M N shell is 8
Therefore the number of electron found in the outermost shell becomes the number of Valence electron in that element.