Answer;
-Noble gases or Group 18 elements
Explanation;
A full valence shell is the most stable electron configuration. Group 18 elements or noble gases such as helium, neon, and argon, have a full outer, or valence, shell. Elements in other groups have partially-filled valence shells and gain or lose electrons to achieve a stable electron configuration.
They are extremely unreactive and do not form bonds with themselves. Solid helium is the the ultimate fine powder being monotomic.
<span> the water compound of </span><span>H2O</span><span>. hope this helps </span>
Sanderson's cross-national study indicated that international migration increases overall levels of human development. Thus, the correct option is A.
<h3>What is Migration?</h3>
Migration may be defined as the movement of people from one place to another in search of resources better than their native one.
International migration increases the overall standards of human development because it initiates new opportunities and trade aspects of people of one country to another.
It also leads to improved human development outcomes in major areas like education, health, and finance.
Therefore, the correct option for this question is A.
To learn more about International migration, refer to the link:
brainly.com/question/25198210
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After crystal violet staining, the Gram-positive bacteria may appear dark blue or violet. The cell wall of gram positive bacteria have thick peptidoglycan layer, thus it retains the crystal violet stain compared to gram negative bacteria.
