module 3- periodic table and energy Flashcards
how many elements when Mendeleev arranged the pt
60
Mendeleev arranged the table by …
in order of atomic mass
what did Mendeleev do that was special
left spaces for undiscovered elements
when were protons discovered
(1900)
Ekasilicon - undiscovered element
found in (1886) and named germanium
(2014) - the period table has …
-114 elements
- 7 horizontal periods
- 18 groups
how is the pt arranged
in order of increasing atomic number, each succesive element has an extra proton
groups
the elements are arranged in vertical columns called groups, each element in a group has atoms with the same number of outer shell electron and similar properties
periods
horizontal rows - number of highest energy electrons hell in an elements atom
periodicity properties
- Electron configuration
- Ionisation energy
- Structure
- Melting points
chemistry is determined by
electronic configuration - particularly the outer, highest energy electron shell
trends across a period
each period starts with a new electron in its new highest energy shell
across p2
the 2nd subshell fills with 2 electrons, followed by the 2p subshell with six electrons
across p3
the same pattern of filling shells as 2 is repeated for the 3s and 3p subshells
across p4
although the 3d subshell is involved, the highest shell number is n=4, only the 4s and 4p shells are occupied
trends-group
Elements in each group have atoms with the same amount of electrons in their outer shell. Elements in the same group also have atoms with the same number of electrons in the subshells - gives the elements the similar chemistry
blocks of the periodic table
s,p,d,f
new periodic table column numbers
1-18
group 1 name
alkali metals
group 1 elements
Li,Na,K,Rb,Cs,Fr
group 2 name
alkaline earth metals
group 2 elements
Be,Mg,Ca,Sr,Ba,Ra
group 3-12 name
transition elements
group 15/5 name
pnictogens
