22 periodicity 2 Flashcards
what is the trend in nuclear charge across p3?
increase
what is the trend in shielding across period 3?
same amount of shielding
what is the trend in atomic radius across period 3?
decreases across period 3
why does atomic radius decrease across period 3?
increase in nuclear charge
same shielding
electron shells held closer to the nucleus
does electronegativity increase or decrease across period 3?
increase
why does electronegativity increase across period 3?
increase in nuclear charge
same shielding
elements increasingly capable of taking electron density from covalent bond
does 1st ionisation energy increase or decrease across period 3?
electron held more tightly and require more energy to be removed
what are 2 exceptions in physical properties across period 3?
Al has lower 1st ionisation energy than Mg
S has lower 1st ionisation energy than P
why does Al have a lower first IE than Mg?
Mg has 3s e- removed
Al has 3p e- removed
3p higher energy than 3s
why does S have a lower 1st IE than P?
P has 2p e- removed which are unpaired
S has 3p e- removed which are paired
electron pair repulsion
across period 3, which 2 elements does the melting point increase between?
Na and Al
why does the melting point increase from Na to Al?
nuclear charge increases
atomic radius decreases
increase in strength of attraction between metal ions and delocalised electrons
which period 3 element has the highest melting point?
silicon
why does silicon have the highest melting point?
macro molecular structure
lots of STRONG covalent bonds
what structure and intermolecular forces do the non metals in period 3 have? (S8, P4 and Cl2)
simple molecular
van de waals