Kimyodan masalalar yechishda rioya qilinishi zarur bo`lgan asosiy qoidalar

Guruh	Oksidlanish darajasi	Valentlik		Element	Guruh	Oksidlanish darajasi
Valentlik
I	0, +1	I		F	VII	-1,0	I
II	0,+2	II		O	VI	-2,-1,0,+2	II,III, IV
III	0,+3	III		N	V	-3,-2,-1,0,+1,+2,+3, 4,+5	I, II, III, IV
IV	-4, 0, +2, +4	IV, II		B	III	0,+3	III,IV
V	-3, 0, +l,+3, +5	V, III, I		Be	II	0,+2	II, IV
VI	-2, 0, +2, +4, +6	VI, IV, II		Cu	I	0,+l,+2	III
VII	-1,0,+1,+3,+5,+7	VII, V, III, I		Au	I	0,+3	III

Yuqoridagi element atomlari ushbu qoidaga bo `ysinmaydi
Elementlar va ularning birikmalarining xossalarini davriy o’zgarishi
(xossa strelka yo’nalishi bo’ylab ortadi)

	Guruh boylab o`zgarishi	Davr bo`ylab o`zgarishi
Nisbiy elektromanfiylik qiymati	kamayadi	ortadi
Elektronga moyillik	kamayadi	ortadi
Ionlanish potensiali	kamayadi	ortadi
Oksidlavchilik	kamayadi	ortadi
Qaytaruvchilik	ortadi	kamayadi
Atom radiusi	ortadi	kamayadi
Ion radiusi	ortadi	kamayadi
Maksimal valentlik va oksidlanish darajasi	o`zgarmaydi	ortadi
Termik barqarorlik	kamayadi	ortadi
Termik beqarorlik	ortadi	kamayadi
Kislorodli kislota kuchi	kamayadi	ortadi
Kislorodsiz kislota kuchi	ortadi	ortadi
Metallmaslik	kamayadi	ortadi
Asoslik	ortadi	kamayadi
Metallik	ortadi	kamayadi

Turli molekulalardagi bog`lanishlar uzunligi va energiyasi

Bog`lanish hosil qilgan elententlar	Bog` uzitnligi, nm	Bog`lanish energiyasi, kj/mol	Bog`lanish hosil qilgan elementlar	Bog` uzunligi, nm	Bog`lanish energiyasi, kj/mol
H–H	0,150	445,1	F–F	0,142	155,0
Cl–Cl	0,107	238,2	C–C	0,154	356,0
C–F	0,140	448,0	C=C	0,133	610,2
C–Cl	0,176	326,0	C≡C	0,120	836,0
C–Br	0,191	285,0	O=O	0,121	493,6
C–N	0,147	285,0	C=O	0,121	695,0
H–N	0,101	389,0	C=N	0,127	617,0
C–H	0,109	415,0	C≡N	0,115	866,0
C–O	0,143	335,0	N≡N	0,110	945,6

Elementlarning elektromanfiylik qiymatlar qatori

		I guruh		II guruh			III guruh			IV guruh			V guruh			VI guruh			VII guruh				VIII^B guruh
I	1																		H		2,20
II	2	Li	0,97	Be	1,47	B		2,01	C		2,50	N		3,07	O		3,5	F		4,10
III	3	Na	1,01	Mg	1,23	Al		1,47	Si		1,74	P		2,06	S		2,44	Cl		2,83
IV	4	K	0,91	Ca	1,04	Sc		1,20	Tl		1,32	V		1,45	Cr		1,56	Mn		1,60		Fe 1,64 Co 1,70 Ni 1,75