Science, asked by sreenathariniti, 1 year ago

10. Given below are some elements of the modern periodic table :4Be, 9Fe, 14Si, 19K, 20Ca [3](i) Select the element that has one electron in the outermost shell and write its electronicconfiguration.(ii) Select two elements that belong to the same group. Give reason for your answer.(iii) Select two elements that belong to the same period. Which one of the two has biggeratomic size?

Answers

Answered by prmkulk1978
6
Given elements are  Be, F, Si, K, Ca
1) The element that has 1 electron in its outermost shell is potassium -K
Electronic configuration of K is 1s²2s²2p⁶3s²3p⁶4s¹
2)Be and Ca belongs to same group that is second group which is known as alkali earth metals.
Reason: Same valency - 2
so posses same chemical properties and  reactivity properties.
3)Be and F belong to same period that is 2nd  period .
  K and Ca belongs to period 4. 
As the atomic size decreases over period, Be is bigger in atomic size than F.
K is bigger in size than Ca.
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