bond polarity

polar and nonpolar covalent compounds

A covalent compound is a compound in which atoms are held together by covalent bonds. If the covalent bonds are polar, then the covalent compound as a whole may be polar. A polar covalent compound is one in which there is a slight difference in electric charge between opposite sides of the molecule. All polar compounds contain polar bonds. But having polar bonds does not necessarily result in a polar compound. It depends on how the atoms are arranged. This is illustrated in the Figure 1.3. In both molecules, the oxygen atoms attract electrons more strongly than the carbon or hydrogen atoms do, so both molecules have polar bonds. However, only formaldehyde is a polar compound. Carbon dioxide is nonpolar. Q: Why is carbon dioxide nonpolar? A: The symmetrical arrangement of atoms in carbon dioxide results in opposites sides of the molecule having the same charge.

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polar and nonpolar covalent bonds

Covalent bonds are chemical bonds between atoms of nonmetals that share valence electrons. In some covalent bonds, electrons are not shared equally between the two atoms. These are called polar covalent bonds. The Figure than the hydrogen atoms do because the nucleus of the oxygen atom has more positively charged protons. As a result, the oxygen atom becomes slightly negative in charge, and the hydrogen atoms become slightly positive in charge. Click image to the left or use the URL below. URL: In other covalent bonds, electrons are shared equally. These bonds are called nonpolar covalent bonds. Neither atom attracts the shared electrons more strongly. As a result, the atoms remain neutral in charge. The oxygen (O2 ) molecule in the Figure 1.2 has two nonpolar bonds. The two oxygen nuclei have an equal force of attraction for their four shared electrons.

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instructional diagrams

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questions

which type(s) of chemical bonds may be polar bonds?

a) ionic bonds

b) metallic bonds

-->  c) covalent bonds

d) two of the above

which of the following molecules has (have) polar bonds?

a) water

b) carbon dioxide

c) formaldehyde

-->  d) all of the above

all molecules with polar bonds are polar molecules.

a. true

-->  b. false

the oxygen end of a water molecule is positively charged.

a. true

-->  b. false

diagram questions

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