Of its valence electrons or the no. Of valences in its Valence shell .In case of noble gases, their outermost shell is absolutely crammed so no emptiness is available in the outer maximum shell. Thus the oxidation kingdom is 0(zero)for Noble gases. Because, they've complete electrons in their out maximum shell.
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Answer:
Some challenges animals might face when migrating are disease, global climate change, overexploitation, and habitat destruction.
Explanation:
In virtually every corner of the globe, migratory animals face a growing array of threats, including habitat destruction, overexploitation, disease, and global climate change. Saving the great migrations will be one of the most difficult conservation challenges of the 21st century.
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