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.
There are many other potential causes of chest pain, including: 1  shingles â a viral infection of a nerve and the area of skin around it, which causes a painful rash that develops into itchy blisters. 2  mastitis â pain and swelling of the breast, which is usually caused by an infection, most commonly during breastfeeding.