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X CBSE | NCERT Solutions:Carbon and its compound Solved Important...

1.Q. Why carbon form  covalent bond   by sharing electron? Ans: Carbon has four electrons in its outermost shell and needs to gain or lose four electrons to attain noble gas configuration.  (i) it could gain four electrons forming C 4- anion. But it would be difficult for the nucleus with six protons to hold on to ten electrons, that is, four extra electrons. (ii) It could lose four electrons forming C 4+ cation. But it would require a large amount of energy to remove four electrons leaving behind a carbon cation with six protons in its nucleus holding on to just two electrons. Hence, it is difficult for the carbon to lose or gain four electrons therefore  carbon formcovalent bond by sharing electron 2.Q. Why do covalent compounds are in gaseous or liquid state at normal temperature and pressure. Ans: due to Weak Vanderwaal’s forces present between the molecules of covalent compounds.   3.Q. Why do covalent compounds have less melting and boiling points? Ans: As ene

Half Yearly Question Papers 2018-2019

class 9 and 10 Half Yearly Question Papers and Model sample papers class 09 half yearly Sample question paper sep 2018/19 9th maths Half Yearly Exam (2018 – 2019) Sample paper prince public school-1 Download File 9th maths Half Yearly Exam (2018 – 2019) Sample paper prince public school-2 Download File 9th maths Half Yearly Exam (2018 – 2019) Sample paper Bloom public school-3 Download File 9th science Half Yearly Exam (2018 – 2019) Sample paper prince public school-1 Download File 9th science Half Yearly Exam (2018 – 2019) Sample paper prince public school-2 Download File 9th Science Half Yearly Exam (2018 – 2019) Sample paper Bloom public school-3 Download File class 10 half yearly Sample question paper Sep 2018/19 10th maths Half Yearly Exam (2018 – 2019) Sample paper prince public school-1 Download File 10th maths Half Yearly Exam (2018 – 2019) Sample paper prince public school-2 Download File 10th maths Half Yearly Exam (2018 – 2019) Sample paper Bloom public school-3 Downloa

10th Maths Mid-term question paper Sep 2018 SDV

9th Mid-term question paper Sep 2018 SDV

9th Science Mid-term question paper Sep 2018 SDV      See paper 9th Maths Mid-term question paper Sep 2018 SDV        See paper