Razumevanje kemijskih reakcij na ravni delcev pri devetošolcih : magistrsko delo

Zaman, Barbara (avtor), Devetak, Iztok (mentor)

Življenje brez kemije si je v današnjem času težko predstavljati, saj omogoča razumevanje in proučevanje številnih naravnih procesov in pojavov ter nastanka novih materialnih dobrin, ki so del vsakodnevnega življenja. Predmet kemija v osnovni šoli spada med najzahtevnejše naravoslovne vede, saj vsebuje veliko novih in abstraktnih kemijskih pojmov, ki si jih učenci težko predstavljajo in razumejo. Ključ za boljše razumevanje kompleksnih kemijskih vsebin pa je trojna narava kemijskih pojmov, da se lahko pojmi in procesi predstavijo na makroskopski, submikroskopski in simbolni ravni. Največje zanimanje kažejo učenci za makroskopsko raven, saj lahko določene kemijske pojme in procese zaznajo s čutili: vid, sluh, vonj in dotik. Najbolj abstraktna in nezanimiva raven pa je simbolna, saj je treba makroskopska opažanja prevesti v ustrezne simbole, formule oziroma enačbe. Tudi submikroskopska raven se uvršča med abstraktne, saj so makroskopska opažanja razložena na ravni delcev (atom, molekula, ion). Za popolno razumevanje kemije pa ni dovolj razlaga le na eni izmed omenjenih ravni, temveč je treba v proces poučevanja in učenja kemijskih pojmov in procesov sorazmerno vključiti vse tri ravni. V vzgojno-izobraževalnih procesih se za ponazoritev kemijskih pojmov in procesov na ravni delcev uporabljajo submikropredstavitve (SMR), ki predstavljajo analogne modele nekega elementa oziroma spojine. SMR so za učeče na vseh stopnjah izobraževanja ključni dejavnik za učenje in razumevanje kemijske učne vsebine, saj spodbujajo poglobljeno učenje. Pri nepravilni oziroma nedosledni uporabi trojne narave kemijskih pojmov se lahko razvijeta napačno razumevanje in pomanjkljivo znanje kemijskih vsebin. Treba je upoštevati tudi učenčevo predznanje, miselno sposobnost in zahtevnost prehoda med makroskopsko, submikroskopsko in simbolno ravnijo. Nezanemarljivi so tudi učenčeva motivacija, odnos do kemije in zanimanje za učenje trojne narave kemijskih pojmov, ki vplivajo na učenje in uspešnost reševanja nalog v kontekstu. Rezultati dela so pokazali: (1) kje imajo učenci več težav pri branju ali risanju SMR kemijskih reakcij, (2) katere so najpogostejše napake pri risanju SMR kemijskih reakcij, (3) kako učenčev individualni interes, učna samopodoba, zanimanje za učenje trojne narave in kemijskih vsebin vplivajo na njegovo uspešnost reševanja nalog kemijskih reakcij na ravni delcev in (4) ali na uspešnost reševanja nalog vpliva uporaba submikroprezentacij pri pouku kemije. Raziskava je potekala na šestih osnovnih šolah v različnih regijah Slovenije. Sodelovalo je 250 osnovnošolcev, ki so v šolskem letu 2017/18 zaključevali deveti razred osnovne šole, in njihovi učitelji kemije. Rezultati so smiselno podani po sklopih. Ugotovljeno je bilo, da imajo naši osnovnošolci več težav pri risanju kot pri branju SMR kemijskih reakcij, ker pri risanju ne upoštevajo ustreznih veljavnih kemijskih pravil in zakonov. Največ težav pa imajo pri upoštevanju velikosti narisanih delcev, agregatnem stanju kovin, kovinskih oksidov in vodne raztopine soli ter pri upoštevanju stehiometričnega razmerja posameznih elementov na strani reaktantov in produktov. Rezultati kažejo tudi, da imajo učenci težave pri prepoznavanju dvoatomnih molekul, saj so vodik in kisik risali v obliki atomov, ter pri poimenovanju in zapisovanju simbola in molekulske formule. Ugotovljeno je bilo, da so učenci, ki jih bolj zanima učenje kemije, uspešnejši pri reševanju nalog, ki temeljijo na branju in risanju SMR kemijskih reakcij. Na to pa vpliva tudi uporaba submikroprezentacij pri pouku. Učenci, katerih učitelji v pouk kemije pogosteje vključujejo sheme delcev, so uspešnejši pri reševanju tovrstnih nalog. Zbrani podatki kažejo, da ima pri poučevanju in razumevanju kemijskih reakcij na ravni delcev pomembno vlogo učitelj, ki načrtuje pouk. Če učitelj kemijske pojme pogosteje obravnava na treh ravneh ter oblikuje naloge, s katerimi učenci utrdijo in ponovijo usvojeno učno vsebino, učenci bolje razumejo kemijske vsebine in je manj možnosti za razvoj napačnega razumevanja.

• Jezik: Slovenski jezik
• Ključne besede: učenci, učitelji kemije, odnos do kemije, trojna narava kemijskih pojmov, vizualizacija, napačna razumevanja, kemijske reakcije
• Vrsta gradiva: Magistrsko delo/naloga
• Tipologija: 2.09 - Magistrsko delo
• Organizacija: PEF - Pedagoška fakulteta
• Založnik: [B. Zaman]
• Leto izida: 2018
• Št. strani: 69 str., [5] str. pril.
• PID: 20.500.12556/RUL-104324
• UDK: 54:373.3(043.2)
• COBISS.SI-ID: 12145737
• Datum objave v RUL: 09.10.2018

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Nine grade primary school students` understanding of chemical reaction at the submicroscopic level

Izvleček

Life without chemistry is difficult to imagine in today's world. Chemistry enables understanding and research of numerous natural phenomena and the emergence of new consumer goods which are part of everyday life. Chemistry at primary school is one of the most challenging natural sciences because it includes many new and abstract scientific concepts which students find difficult to conceive and comprehend. The key to better understanding of the complex chemistry contents is to appreciate the triple nature of the concepts in order to present chemistry notions and concepts on the macroscopic, sub-microscopic, and symbolic levels. Students gravitate to the macroscopic level the most because they can perceive certain chemistry notions and concepts with their visual, auditory, olfactory, and tactile senses. The most abstract and uninteresting aspect of chemistry for them is the symbolic domain where the macroscopic observations have to be translated into suitable symbols, formulas, or equations. The sub-microscopic level is a part of the abstract domain as well because the macroscopic observations are explained at the level of particles (atom, molecule, ion). However, for a complete understanding of chemistry it does not suffice to offer an explanation based just on one of the domains identified. All three domains must be equally integrated into the process of teaching and the study of chemistry notions and concepts. Schools use sub-micropresentations (SMR) which show analogue models of a particular chemical element or substance to illustrate these notions and concepts in the domain of particulates. The SMR presentations are the key factor in studying and understanding the chemistry syllabus for students at all levels of education because they stimulate in-depth learning. Incorrect or inconsistent use of the triple nature of chemical concepts can lead to misconceptions and deficient knowledge of the chemistry syllabus. Good instruction needs to consider student's previous knowledge, his or her mental ability and the complexity of the transition between the macroscopic, sub-microscopic, and symbolic domains. Other factors, which should not be ignored, are a student's motivation, his or her attitude towards chemistry and interest in studying the triple nature of the chemistry concepts. These factors influence the concepts of learning and affect the student's success in solving the tasks in a particular context. The results of this master thesis show the following: (1) the domains where students have more difficulties in reading or drawing the SMR of chemical reactions; (2) the most common misconceptions which occur in drawing chemical reactions at the sub-microscopic level; (3) how a student's attitude towards chemistry affects his or her success in solving chemical reaction tasks at the level of particulates; and (4) whether the use of sub-micropresentations in chemistry lessons influences the success in solving chemistry tasks. The survey was conducted at six primary schools in different areas of Slovenia. It included 250 primary school students who were finishing the 9th grade of primary school in 2017/2018 and their chemistry teachers. The results of the survey are systematically presented in several topical sets. The results show that Slovenian primary school students have more difficulties in drawing the SMR of a chemical reactions than in reading them because they do not follow the relevant rules and laws of chemistry. Students experience the major share of difficulties in considering the size of the particles they have to draw, determining the aggregate state of metals, metal oxides, and aqueous solutions of salts. Students also find it difficult to consider the stoichiometric relationship between the individual elements of reactants and products. In addition, this research effort reveals that recognizing diatomic molecules poses another problem for students. They would draw the hydrogen and oxygen gases in the form of atoms. Another difficult issue is the naming and writing of a symbol and a molecule formula. The results of the thesis show that students with a greater individual interest in studying chemistry are more successful in solving the tasks, which are based on reading and drawing the SMR of chemical reactions. The level of students' success is affected by the use of sub-micropresentations in chemistry lessons. The students whose teachers often include schematics of particulates in their chemistry lessons are more successful in solving such tasks. The data collected reveals that a teacher's way of a lesson planning results in his or her teaching style and the students' understanding of chemistry reactions at the level of particulates. If a teacher frequently discusses chemistry concepts at each of the three concept domains and prepares tasks, which reinforce and revise the learning of the content, the students understand the chemistry syllabus better and misconceptions are less likely to develop.

• Ključne besede: chemistry, primary education, kemija, osnovnošolski pouk