Answer: 
Explanation:
Electron gain enthalpy is defined as energy released on addition of electron to an isolated gaseous atom.
The amount of energy released will be maximum when the tendency to attract electrons is maximum. As flourine has atomic number of 9 and has electronic configuration of 2,7. It can readily gain 1 electron to attain stable noble gas configuration and hence liberates maximum energy.
Answer:
fitness. the ability of an organism to survive and reproduce in its environment. adaptation. the inherited characteristic that increases an organism's chance of survival.
Because atoms are the small and can't be seen by your eyes. It is so small that scientists need to use a model. A model help scientists study things. So, scientists needs to study atoms using models.
A single sodium ion will combine due to its charge on it
Na^+
The single sodium ion has total one positive charge on it. so it requires only one electron or can bond to one negative charge
in the given polyatomic anions
a) CO3^-2 : it has two negative charge. So it will react with two sodium ions
it will forms Na2CO3
b) PO4^-3 :it has three negative charge. So it will react with three sodium ions
it will forms Na3PO4
c) SO4^-2 : it has two negative charge. So it will react with two sodium ions
it will forms Na2SO4
d) NO3^-1: it has one negative charge. So it will react with one sodium ion
it will forms NaNO3
Hence the correct answer is
Nitrate ion will react with single sodium ion as
Na+ + NO3- ---> NaNO3
