nonpolar covalent bond. (physical chemistry). A bond in which a pair of electrons is distributed or shared equally between two atoms. 1  Facebook.2  Twitter.onpolar covalent bond. (physical chemistry). A bond in which a pair of electrons is distributed or shared equally between two atoms. 1  Facebook.
When is a barrel chest a sign of a disease process? Chronic obstructive pulmonary disease (COPD) is the most common instance in which a barrel chest will occur. In these cases, itâs a sign of the lungs being over-expanded. This is caused by the loss of elasticity and results in the person having hyper-inflated lungs.
Causes Of COPD. COPD is often caused by smoking. Breathing secondhand smoke (someone elseâs smoke), air pollution, chemical fumes, a lot of dust, or other things that bother the lungs and airways over time can also cause COPD. Some people may have a genetic condition that increases their chance of getting COPD.