Answer
In ionic bonding there is a transfer of electrons between oppositely charged atoms(ions). The positively charged atom , the cation donates a proton and the negatively charged ion ( anion) accepts a proton . The donor element is usually a metal and the receiver a nonmetal. Ionic bonding allows two elements to achieve or simulate stable electronic configuration of two or eight electrons in the outer electronic shell( octect rule).
In the formation of table salt sodium chloride(NaCl) Sodium ions with one electron in their outer shell donate that electron to the NaCl bond , while the Chlorine atom with seven electrons in its outer shell accepts an electron from the Sodium atom to complete its outer shell of eight electrons In this way both the Sodium atom and the Chlorine achieves or simulates stable electronic configurations.
Covalent bonds. In covalent bonding , valence electrons are not donated or accepted, but are shared between two atoms with the same or similar degree of electronegativity. In this kind of bonding neither atom can attract or repel the electrons of the bonding pairs, so the result is a pure covalent bond. However, if nonmetals of dissimilar negativity form covalent bonds the covalent bonds will be polar, and the bonded electrons will spend more time closer to the nucleus of the atom of one non-metal than the other. Methane (CH4),ammonia (NH3), and Carbon dioxide (CO2) form nonpolar covalent bonds.
The covalent bonds formed between hydrogen and oxygen in the water molecule are polar covalent bonds : the oxygen atom attracts the electrons more strongly than the hydrogen atom because the former has more protons in its nucleus
Hydrogen Bonding. A hydrogen bond is a weak bond involving an electrostatic attraction between a hydrogen atom bound to electronegative molecule( N, F, O) and another elctronegative molecule or in which a hydrogen atom of one molecule is attracted to an electronegative atom of another molecule.
Hydrogen bonding, as in water results in the Hydrogen becoming positive(+ve) and the oxygen atom becoming negative because of a lone pair of electrons on the oxygen atom.. One consequence is that water molecules are "sticky"that is they attract other water molecules. This occurs because the negative oxygen atom attracts hydrogen atoms but repels negative ions like itself, while the positive hydrogen atoms repel other hydrogens, but attract negative ions like the oxygen ion. The relatively high boiling point and the high surface tension of water are other results of the stickiness of water
Hydrogen bonds are weaker than ionic and covalent bonds
Work Step by Step
Elements are either electronically stable or electronically unstable. The most stable elements have two or eight electrons in their outer or valence electron shell. The noble gases like helium , argon, krypton, and xenon are the most stable electronically -- helium with two valence electrons and the others with eight. Non-noble elements attempt to attain electronic stability by having two electrons in their valence shell( hydrogen) or eight electrons in their valence shells, that is by following the duet or the octet rule.
Bonding is a mechanism by which non stable elements try to attain electronic stability. The three main types of chemical bonding are ionic bonding, covalent bonding, and hydrogen bonding.
Ionic bonds form between strongly electropositive atoms ( usually metals--sodium, potassium etc) and strongly elctronegative non-metal atoms ( chloride, sulfate etc). A metallic atom donate an electron to become a cation and the non-metal atom receives it and becomes an anion. In the process the nonmetal and the metal are bonded chemically to form a salt, in this case sodium chloride (NaCl). Electrons are not shared but given and received.
Covalent bonding takes place usually between non-metallic elements of similar levels of electronegativity. In this kind bonding electrons are shared between a pair of atoms. Neither atom is strong enough to repel or attract the electrons of the bonding pair. The bonding in methane (CH4) and in ammonia (NH3) are examples of covalent bonding between hydrogen and carbon in one case and nitrogen in the other.
In hydrogen bonding the attraction between a proton in one molecule ( H+)an electronegative molecule ( say oxygen) is affected by an electronegative atom in the same or another molecule. Hydrogen bonds form between hydrogen and the elements oxygen, fluorine and nitrogen and others.
