Which of these is not a commonly mined metallic substance?

What is the problem in this article? what solution does the article propose?

Aplant may open end close its stomata to prevent excess water loss and maintain

What is a limitation of using a chemical formula, such as c6h1206, to represent a compound? the chemical formula does not show the types of elements that make up the compound. the chemical formula does not show how the atoms are connected to one another the chemical formula does not show the number of atoms of each element in a molecule. the chemical formula does not show the chemical symbols of the elements in the compound