8.1: Chemical Bond Formation: An Introduction
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Chemical Bond Formation
Bond Types
A bond between an atom with χ = 0.8 and an atom with χ = 1.0 will be:
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metallic, because they are of low electronegativity and the difference is less than 0.5 (χ <2 and Δχ<0.5
A bond between an atom with χ = 0.8 and an atom with χ = 3.5 will be:
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ionic, because the difference in electronegativity is geater than 2 (Δχ >2) .
A bond between an atom with χ = 0.8 and an atom with χ = 2.2will be:
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polar covalent, beacuse the difference in electronegativey is greater that 0.5 and less than 2 (0.5< Δχ < 2.0)
A bond between an atom with χ = 3.0 and an atom with χ = 3.5 will be:
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Covalent because they both have high electronegativity and the difference in electronegativey is less than 0.5 (χ > 3 and Δχ<0.5)
Practice problems
Exercise \(\PageIndex{1}\)
Which of the following groups of molecules contains no ionic compounds?
- HCN, NO2, and Ca(NO3)2
- PCl5, LiBr, and Zn(OH)2
- KOH, CCl4, and SF4
- NaH, CaF2, and NaNH2
- CH2O, H2S, and NH3
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e. CH2O, H2S, and NH3
Exercise \(\PageIndex{2}\)
Which combination of atoms is most likely to produce a compound with ionic bonds?
- B and C
- S and O
- N and F
- Si and Cl
- Mg and O
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e. Mg and O
Exercise \(\PageIndex{3}\)
Which combination of atoms is most likely to produce a compound with covalent bonds?
- K and Br
- Al and S
- S and Cl
- Sn and F
- Li and I
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c. S and Cl
Exercise \(\PageIndex{4}\)
Which of the following pairs of compounds contains ionic bonds?
- KI and O3
- NaF and H2O
- PCl5 and HF
- Na2SO3 and BH3
- RbBr and MgS
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e. RbBr and MgS
Exercise \(\PageIndex{5}\)
Which of the following statements is/are CORRECT?
- Ionic bonds form when one or more valence electrons are transferred from one atom to another.
- Covalent bonds involve sharing of electrons between atoms.
- In most covalently bonded compounds, electrons are NOT shared equally between the atoms.
a. 1 only b. 2 only c. 3 only d. 1 and 2 e. 1, 2, and 3
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e. 1, 2, and 3