Answer:
Germanium
Explanation:
The element Germanium is one with a relative molecular mass of 72. This corresponds to the mass number of this element.
Relative molecular mass of an element is the mass of a formula unit to that of a carbon-12 atom.
The chemical symbol of Germanium is Ge. It is a lustrous and hard metalloid belonging to the carbon group.
It was discovered by Clemens Alexander Winkler.
Answer:
C. naturally uncombined with other elements.
Explanation: Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air.
Answer:
Friston to energy
Explanation:
Friction to Energy as its a energy stooping the object form moving