The atomic mass would not change since the mass of an electron is negligible compared to the mass of protons and neutrons
The given question is incomplete . The complete question is :
In ionic bonding, during the transfer of electrons between two neutrally charged atoms, one electron moves from one atom to another. What are the new relative charges between the two atoms?
a. The giving atom and receiving atom are both negatively charged
b. The giving atom is now positively charged and the receiving atom is now negatively charged.
c. The giving and receiving atom are both positively charged
d. The giving atom is now negatively charged and the receiving atom is now positively charged.
Answer: The giving atom is now positively charged and the receiving atom is now negatively charged.
Explanation:
Ionic compounds are formed by transference of electrons between metals and non metals. The bond formed between a metal and a non-metal is always ionic in nature.
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Thus when one electron moves from one atom to another, the metal acquires a positive charge and the non metal acquires negative charge.
For example:
is formed by transfer of one electron from sodium to chlorine , thus forming
and 
If the moon did not rotate we would see all hemispheres of the moon as it revolves around the Earth and not just the phases.
Explanation :
In thermodynamics, a system is region or part of space which is being studied and observed while the surrounding is the region or space around the system which interacts with the system.
Here in the experiment ,system which is observed is reaction or changes when citric acid and sodium bicarbonate are mixed together. And the mixing is carried out in the calorimeter which serves as a surrounding around the system.
The reason behind the using the calorimeter is measure the energy change occurring during the reaction.