2. Which of the following molecules have polar covalent bonds: H2, N2, HCL, HCN, CARBON DIOXIDE?
1. In ionic bonding, positive and negative ions attract each other and form a strong network structure in which cations (positive ions) surround each other with anions (negative ions) and anions surround each other with cations. These ions come from reactions in which one species loses electrons to achieve a noble gas electron configuration, while another species also gains electrons to achieve an eight-electron noble gas valence shell.
In the covalent bond, neither species loses nor gains electrons. Instead, electrons are shared between the species in the bond. The attraction of each species towards electrons creates the bond.
In metallic bonding, a series of metallic atoms of an element combine and allow electrons to flow freely between them (the key word is delocalized electrons). The nuclei of metal atoms are attracted to the delocalized electrons, causing a bond to form.
2. H2 and N2 are both non-polar covalent bonds. They contain only one species and have a linear geometry. Each atom pulls electrons equally, so no polarity occurs. CO2 is also nonpolar covalent because it is linear, with the oxygens pulling electrons around the carbon equally in opposite directions. Opposite draws cancel each other out.
HCl is polar covalent because the difference in electronegativity between H and Cl is very large, causing electrons to be more attracted to Cl, the species with the highest electronegativity. HCN is also polar covalent. Electrons in the HC bond favor C due to its higher electronegativity, and electrons in the CN bond slightly favor N for the same reason. The H-terminus of the molecule therefore tends to be more positive than the N-terminus.
3. Both HCl and HCN have molecular dipoles. The dipole in HCl has the positive end facing H and the negative end facing Cl. For HCN, the positive end faces H and the negative end faces N.
4. The sp hybrid arises from a sep orbital, so it has two orbitals. sp2 involves one and two p atomic orbitals, resulting in 3 molecular orbitals. sp3 involves one and three p atomic orbitals, resulting in four molecular orbitals. By the same logic, sp3d has 5 molecular orbitals and sp3d2 has 6. A key rule is that there is orbital conservation when atomic orbitals fuse to form bonding orbitals. For example, if two atomic orbitals are lost, two bond orbitals must result.
5. Formal charge is a way to determine the stability of a Lewis structure. It is used to decide which is the best structure when several possibilities arise. It is calculated by taking the initial number of valence electrons in the central atom and subtracting the number of lone pairs and subtracting 1/2 times the number of shared electron pairs (those involved in bonding with other atoms).
this is when metal atoms share electrons. like, Na and K