Topic 2-Bonding

Electrostatic attraction between positive ions and a sea of delocalised electrons. Metals are malleable and ductile

Metallic bonds depend upon the amount of protons The more protons the stronger the metallic bond as greater nuclear charge pulls in valence electrons This increases boiling and melting point as more energy required to overcome metallic bonds

Bond between positive and negative ions held together by electrostatic forces of attraction Involves transfer of electrons High Melting point Soluble in water as they are charged Does not conduct electricity in solids Cannot be shaped Brittle-As repulsion between same charged ions are strong

Electrostatic attraction between positive nucleus and negative electrons It forms between 2 non metals Involves sharing of electrons

Migration of ions on wet filter paper-electrolysis of copper chromate Electron Density Maps

Strong electrostatic forces of attraction between oppositely charged ions so more energy is required to break forces

In solutions,ions are free to move and carry charge so it can conduct electricity In solids,ions cannot move

High Melting Point- as it has strong covalent binds so lots of energy is required to overcome these bonds High strength as each carbon is joined to 4 others so has a coordination no. of 4,strong delocalised electrons Cannot conduct electricity

High Melting Point-Has lots of strong covalent bonds so lots of energy required to break bonds Each Carbon bonded to 3 others Strength- Low strength as it has weak intermolecular forces of attraction so layers can slide over each other Can conduct electricity as it has delocalised electrons

The Greater the charge of the ion,the stronger the Ionic bond and so a higher melting and boiling point The smaller the Ionic radii the greater the Ionic bonding as electrostatic attraction is greater when Ionic radii is small so it is stronger and has a higher melting and boiling point

Ionic Radius increases down the group as atomic number is greater so there is more electron shell

This is where one atom donates both electrons to a bond for example carbon monoxide Contributes to donate both electrons to form a covalent bond

Strong covalent bonds and strong electrostatic forces of attraction allow: Very High Melting points Extremely hard-strong bonds in the regular lattice,so atoms cannot slide past each other Good thermal conductors Insoluble-As atoms are more attracted to neighbours than to solvent molecules Cannot conduct electricity

As you know,pairs of electrons will always repel so stronger repulsion means greater angle difference Lone pairs have stronger repulsion so they have greater angle size

Tendency of electrons to have 8 electrons in the outer shell Elements in the 3rd row or below don’t need to follow the Octet rule as they can have more electrons as they can promote some electrons in a 3d subshell They can have upto 18

Compounds that do not follow the Octet rule and can have more than 8 electrons in a subshell

Is the overlap of a covalent bond which passes the internucleaur axis Single bonds are sigma

Pi bonds are a bond between 2 covalent bonds where it passes the internucleur axis Double bonds have 1 sigma and 1 pi bond Triple bonds have 1 sigma and 2 pi bonds

An uncharged group of 2 or more atoms stuck together

Its where 2 pairs of electrons are shared between 2 elements

Greater relative atomic mass means that there is more electrons and greater nuclei distance so that means the length of the covalent bond is greater.

The Greater the proton number,the greater the attraction between positive nuclei and outer electrons so this means atomic radius is smaller so length of covalent bond is smaller

They are represented by 2 dots or 2 crosses or as an arrow

An element/atom needs a lone pair of electrons to form a full outer shell It requires an acceptor and a donor