18. (a) An element has an atomic number 16. State:
(i) the period to which it belongs.
(ii) the number of valence electrons.
(iii) whether it is a metal or a nonmetal.
(b) Define the following terms:
(i) Ionisation potential
(ii) Electron affinity
The oxidising power of elements increases on moving
from left to right along a period in the periodic table.
Give a reason.
[2011]
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Answers
The element is sulphur
It belongs to period 3.
the valence electrons are 2 (negative).
It is a non metal.
The energy required to remove an electron completely from its atom is called ionisation potential.
Electron affinity is defined as change in energy of a neutral atom when an electronic is added to atom to formally a negative ion.
Answer:
a
1- it belongs to period 3 and the atom is sulphur.
2 - there are 6 Valence electrons
3- It is a non- metal.
B
Ans 1 - The energy required to remove an electron from an isolated gaseous atom, thereby coverting it into a positively charged ion is called ionisation potential.
Ans 2- It is defined as, the amount of energy released by an isolated gaseous atom of an element in its lowest state of energy by accepting an electron to form an anion. The unit of electron affinity is electron volt (eV).