Asked in ChemistryAtoms and Atomic Structure
Atoms and Atomic Structure
When hydrogen and oxygen bind to one another the electrons are pulled?
If a pair of electrons is unequally shared between two atoms what occurs?
In H2O the electrons are shared by the oxygen atom and two hydrogen atoms. Although there are two hydrogen atoms, the electro-negativity (or ability to attract electrons) of the oxygen is greater than the hydrogens, therefore the electrons are pulled greater towards the oxygen resulting in the oxygen becoming "negatively charged" this results in the molecule becoming what is known as a "dipolar molecule". This is what causes water to be attracted to each other as each molecule has a positive and negative pole. Answered by Mason Rawling-Jones (currently 15).
What happens to the polarity of oxygen atoms as they transform from molecular oxygen into water molecules?
In the bond in molecular oxygen, the electrons are pulled equally towards each element, as they are the same element and so have the same electronegativity. In water, however, the bonds are between hydrogen and oxygen. The nucleus of oxygen has eight times the charge of the nucleus of hydrogen, and so attracts the electrons more strongly than hydrogen does. It does not attract eight times as strongly as hydrogen as the extra electron shell repels the electrons in the bond more than hydrogen's nonexistent shells (its only electron is in the bond). It can therefore be said that oxygen is more electronegative than hydrogen. As the oxygen attracts the electrons more strongly than the hydrogen, it gains a partially negative charge. Similarly, the hydrogen gains a partially positive charge. This polarity is responsible for the interesting properties of water, including its ability to stay liquid at room temperature, its low density as a solid and its ability to climb up a narrow capillary tube without any force applied to it.