Atomic Structure and the Periodic Table Flashcards
1
Q
definition for ‘relative atomic mass’
A
the mean mass of an atom of an element relative to 1/12 of the mass of 12C isotope
2
Q
why do noble gases have a low melting point?
A
they are monoatomic
3
Q
why does silicon have a high melting point?
A
silicon is macromolecular
lots of strong covalent bonds which require a lot of energy to break the bonds
4
Q
why do molecules like phosphorous have a low melting point?
A
because they are simple covalent structures
between the molecules are weak London forces which require little energy to break
5
Q
why does first ionisation energy of the elements decrease down the group?
A
electron is being removed from a higher energy level subshell
