If the crucible wasn't covered with a lid the reactants may have produced a gas that was released into the surroundings, or mass may have been lost in the form of water vapour.
<span><span>Number of Protons-19 </span><span>Number of Neutrons-20 </span><span>Number of Electrons-<span>19</span></span></span>
Proton gives nucleus positive charge P+
Answer:
when silver articles exposed to air silver racts with Sulphur present in the atmosphere and form a black layer of silver sulphide on the surface. copper articles get tarnished by reacting with air and water. due to this, a layer is formed over copper vessels.
