Answer:
John Dalton
Explanation:
John Dalton in 1808 suggested that all matter consists of tiny particles called atoms and that the atoms of a specific element are identical.
He postulated the Dalton's atomic theory which has the following important parts;
- All matters consists of indivisible particles called atoms
- Atoms of the same element are similar and are different from atoms of other elements.
- Atoms can neither be created nor destroyed.
- Atoms combine in simple whole ratios to form compounds.
Answer : Electron affinity (Eea) of an atom or molecule can be defined as the amount of energy released or spent when an electron is being added to a neutral atom or molecule in the gaseous state to form a negative ion.
Chlorine is considered to be the element which has highest electron affinity in the modern periodic table.
The general formula is X +
---->
+ energy
It is found that nonmetals have more positive Eea than metals.
Electron affinity increases across the group from left to right in the modern periodic table. Elements with small nucleus have high electron affinity.