C. The mass number is the amount of Protons and electrons there are combined, so 200 - 80 is 120.
In Virginia, the continental divide separates the New River from the Roanoake and James River. East of the continental divide, the rivers flow east or south toward the Atlantic Ocean. West of the continental divide, the rivers flow north or west toward the Gulf of Mexico by way of the Ohio and the Mississippi Rivers.
Galileo disproved the Ptolemaic theory, sanctioned for centuries by the Church, which held the Earth to be the central and principal object in the universe, about which all celestial objects orbited.
Answer:
A
Explanation:
Element A has 3 electrons in outermost shell so its valency is 3. It will loose 3 electrons to attain stability, as loss of 3 electrons is easier than gain of 5 electrons.
Valency of B is −2 as it will gain 2 electrons to attain stability and combine with other atom.
Valency of A⟶+3
Valency of B⟶−2
(Refer to Image)
Cross multiply valency of A and B
∴A2B3 compound will be formed.
2 × (atomic mass of Ag) + (atomic mass of Cl (
