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.
COPD caused by chronic bronchitis is an inflammation of your main airways and increased mucus production, while COPD caused by emphysema damages your air sacs and the smaller airways in your lungs. You also may experience a chronic cough with coughing up mucus, chest tightness, wheezing and difficulty breathing.