An atomic mass unit (symbolized AMU or amu) is defined as precisely 1/12 the mass of an atom of carbon-12. The carbon-12 (C-12) atom has six protons and six neutrons in its nucleus. In imprecise terms, one AMU is the average of the proton rest mass and the neutron rest mass.
Atom is the smallest unit retaining properties of elements
Answer:
the answer is d only as
ca reacts
mg reacts
k is more reactive so no reaction
mg is less reactive than sodium