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.
Conditions that may cause chest pain include: 1  coronary heart disease (CHD, which is caused by plaque buildup and blockages in arteries or atherosclerosis) 2  pulmonary embolism or obstructions in the lung arteries. 3  infection of the lungs.  anxiety and panic 1  attacks. hypertrophic cardiomyopathy (a thickening of the heart muscle)  congestive heart failure.