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how can I know that in any molecule which type of bond is present i-e ionic or covalent...

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msnewbooklover | Student, Grade 9 | Honors

Posted August 5, 2012 at 5:57 PM via web

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how can I know that in any molecule which type of bond is present i-e ionic or covalent bond?

plz explain in easiest manner ....ill be thankful

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sanjeetmanna | College Teacher | (Level 3) Assistant Educator

Posted August 15, 2012 at 11:56 PM (Answer #1)

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Ionic compounds are formed between metals and non-metals.

Covalent compounds are formed between non-metals.

Metallic compounds are formed between metals

Electronegativity it is the tendency of an atom to attract electron more towards it self. If electronegativity difference between atoms is more then it form ionic bond and if it is less then it forms covalent bond.

If the difference is between 0.0 to 0.4 it will form nonpolar covalent bond

If the difference is between 0.4 to1.7 it will form polar covalent bond

If it is >1.7 it will form ionic bond

Ionic compound will have high melting point and conduct electricity. Covalent compounds it has low melting point. Ionic compounds are crystalline solid and covalent compounds exists in three different states of matter that is solid liquid and gases at STP. 

Examples...

Ionic compound = NaCl, CaCO3, Na2O, KNO3...

Covalent compound = H2O, NH3, Ccl4...

Sources:

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thumbsdwn | Student, Grade 11 | eNoter

Posted August 5, 2012 at 7:48 PM (Answer #2)

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You can tell whether it is ionic or covalent by knowing if the elements that were bonded were metal or non-metal. For example:

 

Ionic= Metal + Nonmetal

Covalent= Nonmetal + Nonmetal

*There are some exceptions to theabove rules however, so you should go look at the exceptions to the rule*

 

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kavya--kammana | Student, Grade 12 | Valedictorian

Posted August 20, 2012 at 6:18 AM (Answer #3)

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If electronegativity difference between 2 elements is 1.7 or greater than 1.7 it is ionic bond.

in other words, if constituent elements are metal and non metal it is ionic bond.

if electronegativity difference between 2 elements is below 1.7 the bond formed is covalent bond

eg: oxygen - 3.5

      chlorine - 3

      nitrogen - 2.7

      sodium - 0.90

so difference btw sodium and chlorine is ( nacl)

   3.00 - 0.90 =  2.1

2.1 is greater than 1.7

so the bond formed is ionic bond.

 

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