Foundation Of Chemistry

atoms of the same element with the same number of protons and electrons but different number of neutrons

same chemical properties as same number of outer electrons/same electron configuration however, they have slightly varying physical properties such as densities

The weighted or average mass of the atoms of an element compared to 1/12th of carbon-12

the mass of an isotope of an element compared to 1/12th of carbon-12th

strong electrostatic attraction between oppositely charged ions

A shared pair of electrons between two nuclei

A shared pair of electrons in which one atom provides both electrons

2 or more atoms covalently bonded (intermolecular forces are forces between molecules)

Strong electrostatic attraction between positive metal ions and mobile delocalised electron

Simplest whole number ratio of atoms of each element in a compound

Actual number of atoms of each element in a compound

metals and graphite have mobile delocalised electrons molten or aqueous ionic compounds have mobile ions

Solid ionic compounds have ions fixed in lattice molecules have no mobile charge carriers (ions or electrons)

giant structures (metallic ionic and covalent) have high melting and boiling point because it requires large amount of energy to break strong metallic ionic and covalent bond throughout the giant lattice whilst simple molecules have low melting points due to its weak intermolecular forces, so it requires little energy to break these forces

high melting point because of its strong electrostatic force of attraction between positive metal ion and negative delocalised electrons

they have high melting and boiling point because it takes a lot of energy to break the strong ionic bonding throughout giant ionic lattice they can conduct electricity in molten due to mobiles ions they can not conduct electricity in solid as there ions are in a fixed lattice

do not conduct electricity when solid or molten as they dont have no mobile charge carriers however carbon in the form of graphite can conduct electricity because they are delocalise electron which are mobile

GRAPHITE giant covalent molecule so it takes a lot of energy to break strong covalent bonds DIAMOND *giant molecule *each carbon has 4 strong covalent bonds *high melting + boiling point because of its strong covalent bonds *No mobile delocalised electrons

Boron Carbon Silicon

Is the average mass of a molecule compared to 1/12th of a mass of one atom of carbon-12

*Sodium conducts in its solid and molten state *sodium has delocalised electrons in both solid and liquid state *sodium oxide conducts in molten but not solid *molten sodium oxide has ions which are mobile *solid sodium oxide has ions which are in a fixed position in an ionic lattice structure

*repeating pattern *oppositely charged ions