Emotional and Cognitive Preservice Science Teachers' Engagement While Living a Model-Based Inquiry Science Technology Engineering Mathematics Sequence About Acid-Base.

Science inquiry and modeling activities have been proved to heighten emotional situations; therefore, research about emotions should aim to identify which activities promote student engagement with Science, Technology, Engineering and Mathematics fields through multidimensional models that include emotional and cognitive engagement. This research is focused on science teachers' need to carefully review their classroom instructions to ensure that students are provided with opportunities to develop appropriate understandings of acid/base models (and their concepts). To achieve this, we have implemented a short model-based inquiry acid-base instructional sequence in the context of a TV-spot about chewing gum. A descriptive, non-experimental quantitative methodology with a heuristic (emotional: self-report questionnaire; and cognitive: self-regulation questionnaire) has been used to analyze what Pre-Service Secondary Education Teachers from several Spanish universities recognize to have learned and felt in each activity. Differences regarding knowledge declared by the participants were identified in all the tasks from before to after carrying them out. Furthermore, the results seem to indicate that there are significant relationships between the knowledge and the emotions, being different depending on the skill involved. Significant correlations between emotions have been found. However, there were no significant correlations with either rejection and knowledge or with other emotions, which points to emotional engagement. Generally, no significant differences were identified between emotions and gender or universities, with some exceptions between genders in two tasks. Thus, the results led us to reflect on the instructional sequence implementation's ability to bring awareness to the learning process and how it produces multidimensional engagements.

Changing How We Teach Acid-Base Chemistry: A Proposal Grounded in Studies of the History and Nature of Science Education.

We propose explicit and implicit approaches for the teaching of acid-base chemistry based on research into the history and nature of science (NoS). To support these instructional proposals, we identify four rationales for students to understand acid-base processes: daily life, socio-scientific, curriculum, and history of science. The extensive bibliography on misconceptions at all educational levels justifies the need for a change from the usual pedagogical approaches to teaching the acid-base domain (traditionally involving conceptual-focused teaching) to a deeper and more meaningful approach that provides (implicitly or explicitly) a chance to reflect on how scientific knowledge is constructed. Controversial moments in science from 1923, when three researchers (Bronsted, Lowry, and Lewis) independently enunciated two theories from two different paradigms (dissociation and valence electron), underpin our first sequence with an explicit NoS approach for both lower secondary school and upper secondary or university levels. Our inquiry teaching cycle promotes the transformation of a hands-on activity (using cabbage as an indicator) into an inquiry, and subsequently, we use an historical model to propose a sequence of activities based on the modeling cycle of Couso and Garrido-Espeja for lower secondary school. Finally, we identify some implications for a model-focused teaching approach for upper secondary and university levels using more sophisticated models.

Blocking and bridging ligands direct the structure and magnetic properties of dimers of pentacoordinate nickel(II).

Dinuclear pentacoordinate nickel(ii) complexes of the formula [(NiTp*)2(µ-L)] (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate; L = oxalate (); oxamate (); oxamidate (); OC(4-Cl-C6H4N)C(4-Cl-C6H4N)O ()) and {[Ni(N3-mc)]2(µ-L)}(PF6)2 (N3-mc = 2,4,4-trimethyl-1,5,9-triazacyclododec-1-ene; L = oxalate (); oxamate ()) have been synthesized and spectroscopically characterized (IR, (1)H NMR). X-ray structures of show nickel(ii) in a square pyramidal geometry and different supramolecular interactions. Magnetic measurements for show strong antiferromagnetic interactions across the bridging ligand [: J = -36.8 cm(-1), g = 2.16; : J = -43.6 cm(-1), g = 2.12; : J = -51.1 cm(-1), g = 2.12; : J = -39.7 cm(-1), g = 2.18; : J = -35.4 cm(-1), g = 2.20; : J = -44.3 cm(-1), g = 2.18]. Magneto-structural correlations between the magnitude of the magnetic coupling and the different blocking ligands, the different bridging ligands, the distortion of the coordination environment of Ni(ii) and the planarity between the bridging ligand and the basal plane of the Ni(ii) environment have been established for all complexes.

Structure and spectroscopic properties of nickel benzazolate complexes with hydrotris(pyrazolyl)borate ligand.

The reaction of benzazole ligands 2-(2'-hydroxylphenyl)benzimidazole (Hpbm), 2-(2'-hydroxylphenyl)benzoxazole (Hpbx), and 2-(2'-hydroxylphenyl)benzothiazole (Hpbt), with [Ni(Tp*)(µ-OH)]2 (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate), leads to pentacoordinate nickel complexes [Ni(Tp*)(pbz)] (pbz = pbm (1), pbx (2), pbt (3)). The structures of 1, 2, and 3 were determined by X-ray crystallography. The pentacoordinate nickel complexes have distorted trigonal bipyramidal geometries with Addison's τ parameter values of 0.63, 0.73, and 0.61 for 1, 2 and 3, respectively. The benzazolates are bonded in an η(2)(N,O) fashion to the nickel atoms. DFT calculations are carried out to optimize the structures of the three complexes giving a good agreement with the X-ray structures. The (1)H NMR spectra of complexes 1-3 exhibit sharp isotropically shifted signals. The complete assignment of these signals required an application of two-dimensional {(1)H-(1)H}-COSY techniques. The experimental absorption spectra of the three complexes in chloroform solution each show an intense absorption band in the ultraviolet region ca. 240 nm, followed by three less intense bands, the first two at ∼295 and ∼340 nm, and the last more disperse one, at wavelengths between 360 and 410 nm. The absorption spectra are simulated by TD-DFT and reproduce the main features of the experimental spectra well. The analysis of the electronic transitions by inspection of the frontier molecular orbitals and also the natural transition orbitals allowed us to characterize and assign the observed bands properly. The three complexes are moderately blue luminescent at room temperature, both in the solid state and in solution. Emission spectra at room temperature display broad structureless bands in chloroform solution at 460, 482, and 512 nm for complexes 1, 2 and 3, respectively, and structured emission in solid state with λmax values of 473, 486, and 516 nm. Complexes containing different donor atoms in the benzazole ligand are furthermore observed to give different luminescence responses in the presence of Zn(II), Cd(II), Hg(II), and Cu(II).

Crystal structures and magnetic properties of nickel complexes with hydrotris(pyrazolyl)borate ligand and double bridged by phosphate esters.

The reaction between [NiTp*(µ-OH)]2 (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate) and (RO)2P(O)OH (R = Et, Bu, 4-NO2-Ph) affords the dinuclear nickel phosphates [NiTp*(µ-O2P(OR)2)]2 (R = Et (1), Bu (2), 4-NO2-Ph (3)), which have been studied by spectroscopic methods (IR, UV-vis, and (1)H NMR). In chloroform solution, those complexes exhibit isotropically shifted (1)H NMR resonances. Their molecular structures reveal that they all have an eight-membered Ni2O4P2 ring which possesses two nickel centers bridged to each other by two isobidentate phosphate ligands. Magnetic studies on 1-3 and other similar complexes (4 and 5) reveal antiferromagnetic behavior at low temperatures as well as an interesting correlation between calculated D values and the planarity of eight-membered Ni2O4P2 rings.