Elements that can be very dangerous but form useful materials when combined with other elements Answer Choices:
Atomic Mass
Atomic Number
Halogens
Metals
Noble Gases
Non - Metals

Halogens

Explanation:

Halogens include elements like Fluorine, Chlorine, Iodine and Bromine. These  elements can be dangerous to humans especially when used in large quantities.

When combined with other elements however, they can form very useful materials. Chlorine for instance forms salt when combined with sodium. Fluorine becomes very useful in toothpaste to protect teeth and bromine can be used in pesticides.

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