The group VIA elements are called chalcogens because most ores of copper (Greek chalkos) are oxides or sulfides, and such ores contain traces of selenium and tellurium.
Answer:
It is a physical change.
Explanation:
While it is a chemical reaction because the salt gets dissolved, if you were to boil the water off of a salt solution, all that would be left is salt. This can be done physically. Thus, it is a physical change.
Answer:
a formula giving the proportions of the elements present in a compound but not the actual numbers or arrangement of atoms.
Explanation:
Electric current is the flow of electrons in a wire. ... They are no longer firmly held by a specific atom, but instead they can move freely through the lattice of positive metal ions