超一流的化学高手、化学专家请进(Periodicity0005)WhatpropertyofthefirstsixelementsofPeriod3(sodiumtosuplphur)continuouslyincreasenumerically?Whatarethetrendsconcerningperiod3elementsfromsodiumtochlorine?Element

Question

超一流的化学高手、化学专家请进(Periodicity 0005)
What property of the first six elements of Period 3 (sodium to suplphur) continuously increase numerically?
What are the trends concerning period 3 elements from sodium to chlorine?
Elements Q and R are from period 3.
(a) Element Q forms an oxide that is soluble in both acidic and
alkaline medium.
(b) Element R forms an oxide that is insoluble in water but soluble
in alkali.
State,giving reasons,the identity of each element.
Write balanced equations for any reactions that take place.
Thanks.

Answer 1

1,their non-metallic property increase numerically
2,their atom size decrease from sodium to chlorine
3,Q is the Al which form Al2O3 with oxygen.It is an amphoteric oxide.
4Al+3O2==2Al2O3 Al2O3+6HCl=AlCl3+3H2O Al2O3+NaOH==NaAlO2+H2O
R is an non-metallic atom so that it may form a oxide that will solute in alkali.So it may be the SiO2.So R is Si.
SiO2+2NaOH==Na2SiO3+H2O