periodicity 8 Flashcards
periodic table
order of increasing atomic number
can predict the properties depending on its position
groups
- the vertical column of elements
- similar chemical properties
- same number of electrons
reactivity
s-block metals = get more reactive going down the group
transition metals = non-reactive
periods
-horizontal rows
placing hydrogen
-forms a 1+ ion but not chemically similar and is also a gas
placing helium
-not a p-block element 1S2
group 1,2,3 elements bonding
giant structure
ionic compounds
metallic bonding
group 4 elements bonding
four covalent bonds (giant covalent)
group 5,6,7 elements bonding
non-metals
covalent bonds
group 0 (8) element bonding
noble gas
full outer shell
unreactive
melting and boiling point
1 - group 4
2- group 3,2,1
3- group 6,5,7
4-group 8
atomic radii
taken to be half the distance between the centres of a pair of atoms
the size of the atom ……. going across a period
decrease
radii of the atoms increase down a group
going down a group an extra shell of electrons are added, the electron is further away from the nucleus
why does the first ionisation energy increase across a period
a number of protons in the nucleus increases but the electrons enter the same shell. so it gets increasing difficult to remove an electron