Chemistry SHARE~~

Its all the details tat i get from my tuition teacher, it nice to share wit ur guys lo~~

In periodic table in F4 chapter 4, G1 element r known as Alkali Metal(haiz i tink u no ady la) and, do u know?? it is start its reactivity from the TOP to DOWN, and its ELECTROPOSITIVITY will also increasing!! By tat, its density and its size will oso increase, BUT, only the boiling point(BP) and melting point(MP) decrease accordingly~
Y its density n size increase? For density, the increasing of RAM is more than its volume(atomic radius)!! Size le, i tink u all no lo! More shells need to obtain electron(e-)will coz the increasing in size. However, its electronegativity will decrease from G1 TOP to DOWN!!

Metal in G1-G3 is belong to DONATOR, so it is usualy donate atom to non metal to STABLE itself, while non metal in G14-G17 r RECEIVER, then form
an ionic compound!! actualy, there was a skill!! U can even no the no. of molecules from the ions given!!

Question- wats the chemical formulae of potassium, K+ and chlorine, Cl-??

Ans- as we no tat the G1=+1,G2=+2,G3=+3,G17=-1,G16=-2 and G15=-3

K+ is G1, so K+ lo; Cl- is G17, so Cl- lo
from the ions given above, the chemical formulae is KCl!!
do u no y?? if dun no ask me in school ba~~

Last note, very banyak stuff i learned, but a litle note for u!! ELECTRONEGATIVITY is ability to attract e-, and ELECTROPOSITIVITY is its vice versa!! Same no. of valance e- MEANS SAME chemical properties!! in form 5 lesson i lazy to explain, if wan to no jus ask me in school la!! hope u guys get A1 in SPM!!