Khởi động giờ học, một hoạt động quan trọng để nâng cao hiệu quả trong dạy học hoá học trường phổ thông

a

O PGS. TS. LE VAN NAM - TRAN THI TUYET HONG*

Phdt huy tinh tich eye, ty gide, ehu ddng, sdng

tqo vd gdy hirng thii eho hge sinh (HS) trong

hge tdp dang Id mqt trong nhCrng mye tieu

ddi mdi phuong phdp dqy hge (PPDH) quan trqng

hien nay. Yeu edu ndy phdi dugc tien hdnh d td't

ed cdc giai doqn euo qud trinh dqy hoc. Mdt

trong ede yeu td tqo nen thdnh edng eho tiet hge

Id hoqt ddng khdi ddng. Id hoqt ddng ddu tien

khoi ngudn hung thu eho ed thdy vd trd trudc khi

budc vdo bdi hge mdi. Ve mdt tdm li hoc, hung

thu Id tde nhdn quon trqng ddn den sy ty gide;

hung thu vd ty gide Iqi Id hoi yeu to tdm li ddm

bdo sy hinh thdnh vd phdt trien tinh tich eye, ddc

Idp sdng tqo trong hqc tdp. Ve mdt li ludn dqy

hoc, ddy Id budc thir bo trong edu true eua bdi

len Idp (neu vd'n de nghien cuu vd chudn bj tiep

thu kien thire, kT ndng mdi). Mdc ddu vdy, hoqt

ddng khdi ddng ndy chua dugc hudng ddn trong

cdc tdi lieu li ludn dqy hoc cung nhu trong ede

sdeh gido vien (GV). De giup cho hoqt dqng ndy

dugc thudn Igi hon, bdi viet gidi thieu mdt so

hinh thuc lya chqn, ede budc tien hdnh khdi ddng

trong dqy hoc hod hge md chung tdi dd thyc hien

cd hieu qud d trudng phd thdng.

Ve hinh thue khdi ddng trong gid dqy hgc

hod hgc

Cd nhieu hinh thire hoqt ddng khdi ddng trong

dqy hoc, viee lya chqn hinh thue ndo phy thudc

vdo ddc thi) euo tirng bd mdn, khdi Idp, ddi tuqng

HS, ddc diem ndi dung kien thue euo bdi hoc, vd

ddc biet Id kien thire eu ndo lien quan den ndi

dung kien thirc mdi. Tren ea sd do, GV lya ehgn

hinh thue khdi ddng nhu the ndo de gdp phdn dqt

hieu qud cao trong gid gidng Id tuy thudc vdo kT

ndng dgy hge euo GV. Trong dqy hoc hod hge d

trudng phd thdng, mdt so hinh thue khdi ddng eho

bdi gidng thudng gdp Id: - Su dyng md hinh, hien

tugng hod hgc thye te mdu thudn vdi kien thirc dd

biet; - Dyo tren cdu tqo nguyen h>, phdn tu; - Su

dyng thi nghiem (TN); - Dung sadd bieu diln mdi

quan he giCra ede chd't; - Su dyng cdu hdi, bdi

tdp; - Dung hinh dnh ung dyng;...

Tap clii Giao due so 25 8 (kia-3/aoii)

Mdt so'VI dy ve hoqt ddng khdi ddng trong

dgy hgc hod hgc

1) Su dyng md hinh, hien tugng thyc te

mdu tbuan vdi kien thue dd biet. Cdeh thiet ke:

- GV chudn bj kT tranh dnh, md hinh,... (chudn bj

trudc khi len Idp); - GV neu vdn de, HS trd Idi,

cdc HS khde bd sung; - GV hodn thien edu trd Idi

vd ddt vdn de vdo bdi mdi.

Su dyng hinh thue ndy ed uu diem Id: - Kiem

tra, ddnh gid vd cung ed kien thue eu euo HS;

- Gdy sy td md, thdc mdc eho HS, kieh thich sy

tim hieu kien thue mdi; - Giup HS cdeh nhd kien

thue quo hien tugng thye te, hinh dnh mot edch

de ddng; - Hinh thdnh vd phdt trien khd ndng

phdn dodn, suy ludn de gidi thich hien tugng cho

HS, gdy hirng thiJ eho HS vdo tiet hge mdi.

Tren eo sd nghien ciru vd thye te dgy hge hod

hgc tqi cdc tiet hgc trong cdc khdi Idp, theo chuang

trinh vd SGK Hod hge (co bdn - CB; ndng coo -

NC) d trudng THPT, chung tdi thdy dqng bdi dp

dyng vdi hinh thire ndy khdng nhieu nhung neu

dp dyng td't thi dd Id mdt edch ddt biet gdy sy

chu y tim hieu kien thue mdi eho HS, chdng hqn

nhu: - Cdc tiet hoc ed li thuye't mdi, ede hgc thuyet

hod hgc hien dqi, hodc ede hien tugng khdng the

dung cdc kien thire ca bdn dd dugc hge de gidi

thich md edn cd kien thirc rdng vd coo hon; - Cdc

tiet hgc ve ede chdt md edu tgo ed phdn gidng

loqi chd't trudc dd dd hge nhung cung ed phdn

khde nen ed tinh chd't hod hge khde (thudng Id

cdc hgp chdt hiru ea). Cy the d cdc khdi Idp vd

chuyen ban nhu sou (xem bdng Ij.

Bdng 1

idp

10

11

12

NC

CB

NC

CB

NC

CB

Cac tiet co the ap dung

3,6,28, 30,36,40,41,72,...

3, 7,29, 30, 55,...

4, 10, 18, 22,42,43,61,62, 75

12, 17, 14,51,58,...

10, 11,23,...

8, 9, 17,...

* Trudng Oai iipc Vinh