The shared valence electrons between two nonmetal atoms is called a covalent bond. Covalent bonds are formed when two atoms begin sharing electrons. The electrons are attracted to the positively charged nuclei of the atoms. A dipole results when electrons in a covalent bond are not shared evenly between the two atoms.ovalent bonds are formed when two atoms begin sharing electrons. The electrons are attracted to the positively charged nuclei of the atoms. A dipole results when electrons in a covalent bond are not shared evenly between the two atoms.
Low blood pressure, often caused due to dehydration is another cause of faintness and light headed feeling. Episodes of light headedness often trigger in summers or on exposure to high temperatures are linked with dehydration and fall in blood pressure.
When this happens, lightheadedness and fatigue may be the first noticeable symptoms that you are losing blood. Heavy menstrual bleeding also can cause this type of lightheadedness. Sometimes the cause of lightheadedness is an abnormal heart rhythm (arrhythmia), which can cause fainting spells (syncope). Unexplained fainting spells need to be evaluated by a doctor. You can check your heart rate by taking your pulse.