Module three Flashcards
what is periodicity
the repeating trend in propertied of the elements
what are three factors that affect first ionisation energy
atomic radius, nuclear charge and electron shielding
how does atomic radius affect first ionisation energy
as the distance of the valence electron from the nucleus increases, the attraction to the nucleus decreases sharply
how does nuclear charge affect first ionisation energy
the more protons in the nucleus of an atom, the greater the attraction between the nucleus and outer electrons
how does electron shielding affect first ionisation energy
inner shell electrons repel outer shell electrons as they are the same charge , this effect is called shielding and it redices the attraction between the nucleus and the outer electrons
why do successive ionisation energies increase
Successive ionization energies increase because for the same nuclear charge (positive pull of the nucleus) there are fewer electrons each time one is removed, thus more energy is required to remove successive electrons.
what do successive ionisation energies allow predicitions to be made about
-the number of electrons in the outer shell
-the group of the element in the periodic table
-the identity of an element
what is the trend for first ionisation energies accross a period
a general increase accross a period and a sharp decrease between the end of one period and the start of the next
what is a giant covalent lattice
huge networks of covalently bonded atoms
what are allotropes
different forms of the same element
what kind of process is ionising an atom
endothermic process
what happens to grpahite and siamond at 3800K and more
they sublime
what do metal elements exist as
giant metallic lattice structures
in what dimesnion is graphene
2 dimensional compound
what factors affects the melting point in metals
the number of delaclised electrons per atom
the size of the metal ion and the lattice structure
