CHEMICAL BONDING

Profile of Reshmi Krishnan

Reshmi Krishnan, M. Sc. Physics (2013) Kerala University

Currently B. Ed. Student at-

Kerala University College of Teacher Education, Kollam

Date of Birth: 15-05-1991

An Aspirant of Physical Science

Proudly presents this blogspot note-

 

INTRODUCTION TO CHEMICAL BONDING

When different elements react and combine to form a compound, chemical bonds must be formed to keep the atoms together. Once these atoms are joined together its usually difficult to separate them.  The atoms can join together by sharing electrons in what is known as covalent bond or they can transfer or accept electrons to form positive and negative ions and form an ionic bond.

Chemical bond refers to the strong electrical force of attraction between the atoms or ions in the structure. The combining power of an atom is sometimes referred to as its valency and its value is linked to the number of outer electrons of the original uncombined atom.

IONIC BONDING

An ionic bond is formed by one atom transferring electrons to another atom to form oppositely charged particles called ions which attract each other.

·         The atom losing electrons forms a positive ion and is usually a metallic element

·         The atom gaining electrons forms a negative ion and is usually a non-metallic element

·         The ionic bond then consists of the attractive force between the positive and negative ions in the structure.

^·          [Na]⁺[Cl]^-The sodium atom transfers an electrons to the chlorine atom in forming the ionic compound sodium chloride.

COVALENT BONDING

A covalent bond is formed by two atoms sharing electrons so that the atoms combine to form molecule .the bond is usually formed between two non-metallic elements in a molecule .The two positive nuclei of both atoms are mutually attracted to the shared negative electrons between them forming the covalent bond. They share the electrons in a way that gives stable noble gas electron arrangement like helium

Presentation of Bonding -------

Quiz Box

1          When light Bends as it enters a different medium the process is known as what?

2.      A magnifying glass is what type of lens?

3.      Electric resistance is typically measured in what units?

4.      A person who study’s physics is known as a ?

5.      Mentals expand when heated and do what when cooled?

6.      What is the first name of the famous scientist who gave us Newton’s three laws of motion

7.      What state of the art computer technology is used to train piolets when wanting to copy the experience of flying an air craft?

8.      Electric power is typically measured in what units?

9.      The most recognized model of how the universe began is known as the ?

10.    Who is the hubble space telescope named after?

11.    The wire inside an electric bulb is known as the what?

12.    Theoretical  physicist James Maxwell was born in what country?

13.    Infrared light has a wavelength that is too long  or short to be visible for humans?

14.    What kind of eclipse do we have when the moon in between the sun and the earth?

15.    True  or analyse? Iron is attracted by magnet?

16.    What  is the earth’s primary source of energy?

17.    Conductors have a high or low resistance?

18.    Electric Current is typically measured in what units?

19.    What scientist is well known for his theory of relativity?

20.    Earth is located in which galaxy?

**********************************************************

Answers:

1.   Refraction

2.   Convex Lens

3.   ohms

4.   Physicist

5.   Contract

6.   Isaac

7.   A flight simulation

8.   Watts

9.   Big bang

10. Edwin Hubble

11. Filament

12. Scotland

13. Long

14. A Solar Eclipse

15. True

16. Sun

17. Low

18. Amperes

19. Albert Einstein

20. The Milky Way galaxy

ajn IY ]d-bp-t¼mÄ

Rm³ ajn.  Ime-§-sf{X-bmbn Rm³ \n§-fpsS IqsS IqSn-bn-«v.  Fs¶-¡p-dn¨v IqSp-X Adn-bm³ \n§Ä Ft¸m-sg-¦nepw {ian-¨n-«pt­m? Fsâ kz´w Iq«p-Imsc Rm³ \n§-tfmSv Fs¶-¡p-dn¨v ]d-bmw.  ]e \nd-¯n-epÅ Fs¶ \n§Ä¡v Hcp-]mSv CjvS-am-sW¶v F\n-¡-dn-bmw. Rm³  shÅ-¯n ebn¡p¶ Hcp-Xcw Nmb-am-Wv.   Rm³ Hcp ip²-]-ZmÀ°-a-Ã.  Pehpw Ifdpw aäp {Zmh-Imw-ihpw IeÀ¶ an{in-X-amWv .  ]nKvsaâ v, Ì_n-sse-tkÀkv, ss_³UÀ, B¡-tlmÄ t]mepÅ HmÀKm\nIv emb-I-§Ä F¶n-h-bmWv F¶n AS-§n-bn-cn-¡p-¶-Xv.  \n§Ä¡v AXv a\-kn-em-I-W-sa-¦n Fs¶ H¶p NqSm-¡n-bm aXn.  NqSm-¡p-t¼mÄ  {Zmh-Imwiw apgp-h³ _mjv]-am-Ipw.  Jcm-h-Ø-bn-epÅ \nd-apÅ ]ZmÀ°w Ah-ti-jn-¡p-¶-Xmbn ImWmw.  \n§-sf-t¸mse Xs¶ F\n¡v {]nb-s¸-«-h-cmWv Ch-scm-s¡.

\n§Ä¡v FÃm-hÀ¡pw \µn-bp-­v.  Fs¶-¡p-dn-¨-dn-bm³ \n§Ä a\-kp-Im-Wn-¨tÃm ?  A£-c-§fpw Ah-bpsS N§m-Xn-I-fmb kpa-\-kp-I-fmb \n§fpw DÅ Imew hsc Rm\pw Iq«p-­v.  \n§-fpsS _p²nbpw, Ign-hp-Ifpw BIm-i-t¯mfw DbÀ¯p-hm³.

                                                       F¶v kz´w

                                                              ajn............

VIDEO PRESENTATION FOR NEWTONS' LAW OF MOTION

VIDEO PRESENTATION ON LARGE HADRON COLLIDER

LESSON PLAN

Name of Teacher        :           RESHMIKRISHNAN              Standard          :           IX

Name of School          :           GMBHSS                                 Strength           :           15/15

Subject                        :           Physics                                     Date                :           18.09.2014

Unit                             :           Ne\w                                    Duration          :           40 min

Topic                           :           aq¶mw Ne\\nbaw          Stage               :           14⁺

CURRICULUM STATEMENTPupil develop Intellectual knowledge, conventional knowledge, procedural knowledge of the concept of third law of motion and its role in our life through observation discussion and experimentation and evaluation by questioning participation in practical work and group discussion.

CONTENT ANALYSIS

Terms:                  \yq«sâ 3þmw Ne\ \nbaw              

Facts:                    shSn-bp­ ]mbn-¡p-t¼mÄ tXm¡v ]pd-tIm«v sXdn-¡p-¶p.

                Hcp h©n-bn \n¶pw HcmÄ Ic-bn-te¡v NmSn-bm h©n ]n¶n-te¡p \o§p-¶p.

                        Hcp tdm¡äv I¯n-¡p-t¼mÄ AXv apt¶m«v ]mbp-¶p.

hmbp \nd¨ _eq-Wn \n¶pw hmbp ]pd¯p t]mIp-t¼mÄ _eq¬

hmbp-{]-hm-l-¯n-s\-Xnsc Nen-¡p-¶p

Duªmen \n¶pw tk^vän-s\-än-te¡v NmSp¶ kÀ¡kv Xmcw apI-fn-te¡v DbÀ¯-s¸-Sp-¶p.

Concept:         GsXmcp {]hÀ¯-\--¯n\pw  Xpeyhpw hn]-co-X-hp-amb Hcp {]Xn-{]-hÀ¯\w                    D­mbn-cn-¡pw.  CXmWv \yq«sâ aq¶mw-N-e-\-\n-b-aw.

Learning Outcome:

            Enables the pupil to develop

1.         Factual knowledge of Newton’s third law by

            a.         Recalling laws of motion

            b.         To Every action there is equal and opposite reaction

            c.         Recognize examples for Newton’s third law

2.         Conventional knowledge on Newton’s third law by

            a.         explaining the concept of Newton’s third law

            b.         Illustrating action and reaction in various situation

            c.         Uses a concept of third law of motion in new or unfamiliar situation.

3.         Procedural knowledge on third law of motion by

            a.         doing many activities

            b.         Raising questions on third law of motion

4.         Different process skill like observing, making operational definition, interring communicating etc.

5.         Attitude toward Science

6.         Metacognition

            Metacognitive knowledge on Newton’s third law of motion and its role in our life  by

            a.         Focusing the idea to every action there in equal and opposite reaction

            b.         Identifying situations in which third law is applicable.

            c.         Find out action and reaction in various situations

Prerequisites:

                        Ne-\- k-a-hm-Iy-§sf¡pdn¨pw Ne-\- \n-b-a-§-sf-¡p-dn¨pw Ip«n-IÄ t\cs¯

a\-kn-em-¡n-bn-«p-­v

Teaching Learning Sources

            Material for experiment

            a.         activity cards

            b.         chalk board drawings

            c.         demonstration, experimentation, observation

Class interaction procedure	Pupil response
Introduced \n§Ä  rubber band hen-¨n-«p-t­m? \n§Ä Hcp rubber ball `n¯n-bn ]Xn-¡p-t¼mÄ AXv Xncn-¨p-h-cp¶p AXnsâ Imc-Ws¯ ]än-bmWv \½Ä C¶p ]Tn-¡p-¶Xv.
Orientation             So¨À Ip«n-Isf {Kp¸p-I-fmbn Xcw-Xn-cn-¡p-¶p.
Presentation             {]hÀ¯\w þ 1 So¨À Hcp Ip«nsb hnfn¨v \S-¡m³ Bh-iy-s¸-Sp-¶p. \nco-£Ww þ kb³kv Ub-dn-bn  Fgp-XpI
NÀ¨ kpN-I-§Ä         1.       \n§Ä Xd-bn-eqsS \S-¡p-t¼mÄ _ew {]tbm-Kn-¡ptam ?      F¦n GXp Zni-                     bn ?         2.       {]tbm-Kn¨ _e-¯nsâ Zni-bn-emtWm þ \n§Ä¡p Ne-\-ap-­m-bXv?
t{ImUo-I-cWw \mw Xd-bn ]nd-tIm«v _ew {]tbm-Kn-¡p-¶p.  CXmWv \mw sN«p¶ {]hÀ¯-\w.  At¸mÄ AXn\p Xpey-amb Hcp _ew Xd \½nte¡p {]tbm-Kn-¡p-¶p. CXmWv {]Xn-{]-hÀ¯\w
{]hÀ¯\w þ 2 c­v  Spring balance H¶n¨v LSn-¸n-¡p-¶p. AXn H¶v \nÝ-e-am¡n sh¨v asäm¶v Xmtg¡v hen-¡p-¶p.  AXn \n¶pw e`n-¡p¶ reading Fgp-Xp-I. \nco-£Ww kb³kv Ub-dn-bn tcJ-s¸-Sp-¯p-I.
NÀ¨ kpN-I-§Ä         1.       c­v  balance epw Hmtcm reading BtWm ?         2.       Chn-Sps¯ {]hÀ¯\w F´mWv ?         3.       Chn-Sps¯ {]Xn-{]-hÀ¯\w F´mWv ? {]hÀ¯-\hpw {]Xn-{]-hÀ¯-\hpw Htc Zni-bn-emtWm ?
t{ImUo-I-cWw         GsXmcp {]hÀ¯-\-¯n\pw Xpeyhpw hn]-co-X-hp-amb {]Xn-{]-hÀ¯\w D­m-bn-cn¡pw.
Application level experience 1.       Hcp t_mÄ `n¯n-bn ]Xn¨v Xncn-¨p-h-cp-¶Xv F´p-sIm­v ?         2.       Hcp h©n-bn \n¶pw HcmÄ Ic-bn-te¡v NmSn-bm h©n ]n¶n-te¡p \o§p-¶p.             Imc-W-sa´v ?                 3.       shSn-bp­ ]mbn-¡p-t¼mÄ tXm¡v ]pd-tIm«v sXdn-¡p-¶-sX-´p-sIm­v ?         4.       \\ª Xd-bn-eqsS \S-¡p-t¼mÄ sX¶n-ho-gp¶p . F´p-sIm­v ?         5.       \o´p-¶-bmÄ apt¶m«v \o§p-¶p.

Review

1.       \yq«sâ aq¶mw Ne\ \nbaw {]Øm-hn-¡p-I.

        2.       shSn-bp­ ]mbn-¡p-t¼mÄ tXm¡v ]pd-tIm«v sXdn-¡p-¶-sX-´p-sIm­v ?

        3.       tdm¡äv I¯n-¡p-t¼mÄ AXv apt¶m«v ]mbp-¶-sX-´p-sIm­v ?

        4.       Hcp h©n-bn \n¶pw HcmÄ Ic-bn-te¡p NmSn-bm h©n ]n¶n-te¡p \o§p-                 ¶p. Imc-W-sa´v ?

        5.       \yq«sâ aq¶mw Ne\ \nbaw _m[I amIp¶ kµÀ`-§Ä Is­-¯p-I.

Follow up activities

1.      \yq«sâ aq¶mw Ne-\-\n-baw _m[-I-am-Ip¶ kµÀ`-§Ä Is­-¯p-I,

2.     {]hÀ¯\-hpw, {]Xn-{]-hÀ¯-\hpw Is­-¯pI