The number of electron shells in elements of period 3.
3 Reason The number of shells present in an atom determines it's period. Hence, element of period 3 will have 3 shells.
The alkali metal in period 2 and the halogen in period 3.
Lithium, chlorine.
State the relation between atomic number and atomic mass for light elements. State which elements are considered radioactive giving reasons.
Electronic configuration of lighter elements shows that the elements which have an even number of proton, for example, atomic numbers like 4He2, 12C6 etc., have their mass numbers twice the…
State the general trend in periodicity in properties of oxides, hydroxides, oxy-acids and hydrides of compounds of elements across a period and down a group.
Below table shows the general trend in periodicity in properties of oxides, hydroxides, oxy-acids and hydrides of compounds of elements across a period and down a group: Across a period…
State how density and melting points of elements varies across a period and down a group.
(i) Density — Density of elements across a period increases gradually to maximum and then it decreases slightly. Down a group density of elements increases gradually. (ii) Melting point — Across a period from…
Explain with reasons the trends in metallic and non-metallic character down a group.
Trends Down a Group: Metallic Character: Increases. Atomic size increases more than nuclear charge, making it easier for atoms to lose electrons. Non-Metallic Character: Decreases. Larger atoms are less likely…
Explain the trends from metallic to non-metallic character of the different elements in the first three periods.
On moving across a period, nuclear pull increases due to increase in atomic number and thus the atomic size decreases. Hence, the elements cannot lose electrons easily. Therefore, metallic nature…
State the factors which affect the metallic and the non-metallic character of elements in a periodic table.
Factors Affecting Metallic and Non-Metallic Character: Atomic size: Larger atomic size means a weaker nuclear pull on the outermost electrons, making it easier to lose electrons. This increases metallic character…