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.
The melting point would decrease
Potential : a yoyo before it’s been released
Kinetic : skateboarding
PH = - log [concentration of H+]
pH = - log [H+]
pH IS A MEAUSE OF ACIDITY AND BASIDITY OF A SUBSTANCE....
AS ACIDITY OF A SUBSTANCE DEPENDS ON THE IONISATION OF H+
THEREFORE IT IS A MEAUSE...
THE LOWER THE PH VALUE, THE MORE ACIDIC IS THE SUBSTANCE