Here are 8 hands-on science experiments for kids over the school holiday. These experiments are great for older children, or with assistance from mum or dad. They can be done at home with ingredients you already have on hand.
experiments in physical chemistry 8t
Looking for K-8 science experiments for kids that will blow your students minds? We've gathered them by grade level and interest so you can find just what you need to get your students excited about science!
Get your students eager to be scientists with these activities and projects. Try one (or all) from your grade level, and then take a minute to browse the experiments in the other grade levels as well. We're sure you'll find several experiments to try this year!
Georg Job and Regina Rüffler are scientists and lecturers with a long experience in teaching physical chemistry at all university levels. The writing of the current book was strongly supported by the "Eduard-Job-Foundation for Thermo- and Matter dynamics." The aim of this foundation is to improve education in natural sciences with particular consideration of a new approach developed by Georg Job.
Take a field trip to Main Event for their How To Bowl Like a Boss Play Academy lab where students use the scientific method with bowling to learn how to perform experiments. The lesson covers variables, hypotheses, and recording results. Play Academy is an accredited STEAM curriculum in partnership with Big Thought and STEM.org that combine educational lessons with the games kids love.
Summary of likelihood scans in the 2D plane of signal strength μ versus Higgs boson mass mH for the ATLAS and CMS experiments. The 68% C.L. confidence regions of the individual measurements are shown by the dashed curves and of the overall combination by the solid curve. The markers indicate the respective best-fit values. The SM signal strength is indicated by the horizontal line at μ=1.
The Earth system consists of numerous physical, chemical, and biological cycles operating to maintain life on our planet as it evolved over the millennia. Within this system, human activities have perturbed the balance of many of these cycles, leading to climate, ecosystem, and biodiversity changes. In the atmosphere, there are acute situations due to the increasing burdens of greenhouse gases that trap heat and of particles that are directly emitted or come from chemical transformations. These can have direct and indirect atmospheric effects, including greenhouse and cloud modifying properties, and negative impacts on human and ecosystem health, crop yields, and quality of life.
Studies of atmospheric composition within megacities have led to significant advances in our understanding of the chemical evolution of urban atmospheres. Recent research has revealed more and more details of the complex processes involved in the atmospheric degradation of volatile organic compounds (VOCs) of anthropogenic (AVOCs) and biogenic (BVOCs) origins, including those processes that lead to incorporation into the aerosol phase. However, important scientific questions remain on how the composition and impacts of urban pollution and biogenic emissions are modified by the mixing of the components of anthropogenic and biogenic air masses. This is significant because it is common that large cities are situated close to forested areas with strong biogenic emissions. A quantitative understanding of the atmospheric chemistry of urban and rural air masses whose trace gas components are combined is needed so that estimates can be reliably made of the impacts of such mixing as the climate changes or because of changes in emissions.
A quantitative understanding of the atmospheric chemistry of urban and rural air masses whose trace gas components are combined is needed so that estimates can be reliably made of the impacts of such mixing as the climate changes or because of changes in emissions.
Instruments deployed at the various sites and platforms will be used to characterize as exhaustively as possible the atmospheric composition, including state-of-the-art measurements of inorganic gases (O3, NOx, NOy, HONO, N2O5, HNO3, CO, CO2, SO2, H2SO4), radicals (NO3, HOx, OH reactivity), gas-phase organic compounds (AVOCs, BVOCs, OVOCs), aerosol composition and physical properties (inorganic and organic species, size distributions, optical properties), emission and deposition fluxes by eddy covariance (CH4, CO2, NH3, O3, NO, NO2, VOCs, H2O, particles), profiles of ozone and aerosols using lidar, and meteorological parameters (winds, radiation by spectroradiometer, temperature and pressure profiles at three heights on the tower, humidity, and boundary layer height by ceilometer).
Each of you will receive two vials: one containing a liquid unknown and one a solid unknown. You will perform a number of experimental procedures on these compounds to gather data. The compounds are part of a finite number of compounds that are listed for you in order of increasing mp and bp. You will determine the actual structure of your unknowns by applying your experimental data to these lists, obtaining a shorter list of possible compounds and performing further experiments to make the final determination.
Reactive oxygen and nitrogen species released by cold physical plasma are being proposed as effectors in various clinical conditions connected to inflammatory processes. As these plasmas can be tailored in a wide range, models to compare and control their biochemical footprint are desired to infer on the molecular mechanisms underlying the observed effects and to enable the discrimination between different plasma sources. Here, an improved model to trace short-lived reactive species is presented. Using FTIR, high-resolution mass spectrometry, and molecular dynamics computational simulation, covalent modifications of cysteine treated with different plasmas were deciphered and the respective product pattern used to generate a fingerprint of each plasma source. Such, our experimental model allows a fast and reliable grading of the chemical potential of plasmas used for medical purposes. Major reaction products were identified to be cysteine sulfonic acid, cystine, and cysteine fragments. Less-abundant products, such as oxidized cystine derivatives or S-nitrosylated cysteines, were unique to different plasma sources or operating conditions. The data collected point at hydroxyl radicals, atomic O, and singlet oxygen as major contributing species that enable an impact on cellular thiol groups when applying cold plasma in vitro or in vivo.
Cold physical plasmas are under investigation in various research fields, such as waste disposal, surface modifications, and medical applications. The latter field is highly attractive as it was already shown that CAPs assist in wound healing1, in the treatment of skin related disorders2, and in cancer treatment3. Plasmas can be designed by various excitation schemes as desired, such as jets, dielectric barrier discharges (DBDs), and other setups4. In addition, numerous feed gases can be used, such as ambient air or noble gases with and without molecular gas admixtures. This variability of plasma sources allows choosing a suitable source for a specific application. However, it also impedes comparison of experimental data or clinical results from different plasma sources. In plasma medicine, this challenge escalates as the biological targets can also vary widely, ranging from in vitro experiments using cellular components5, pro- and eukaryotic cell cultures6,7, animal experiments8, and observational patient studies9. While some general effects in biological targets are described e.g. improvement of blood circulation10 and cell proliferation11, mechanistic investigations on a molecular level are still lacking.
Cold physical plasmas are of interest for the treatment of various medical conditions. While the mechanisms of action is not fully understood, redox related signalling plays an integral part: all plasma source produce a number of reactive oxygen and nitrogen species relevant for signalling processes in vivo. Density and type of species can be tailored by plasma source engineering, yet the ultimate impact on biological systems is rarely revealed. Typically, characterization of a cold physical plasma source focusses on physical aspects, such as electron density, electric fields, or gas phase species distribution and their respective chemistry. As such, both plasma sources investigated in this study are well characterized in the gas phase41,42 and to a limited extent in the liquid phase43,44. While these investigations allow deep insight into the gas phase chemistry of cold plasmas, they only offer a limited idea how plasma derived reactive species affect a biological molecule as the downstream reactions occurring in the liquid phase in interaction with the gas phase are complex. As an example, Sakiyama et al. presented a simulation of a micro discharge in contact with a liquid surface45. While the plasma source differs, various RONS, which are also produced by the sources investigated in this work, were covered by the simulation resulting in 624 reactions, many in dependence to each other. This high complexity indicates the need for better and easy-to-use models at the end of the reaction scheme (=the treated target). To circumvent the extra complexity of a large biomolecule or intact cells/organelles, small target molecules can act as sensor systems for the plasma triggered liquid chemistry. In this regard, some studies with other small molecules, such as tyrosine and phenol, are available for the kINPen (tyrosine)27 as well as for the COST-jet predecessor (the µAPPJ, phenol)22. It was apparent that both sources caused chemical modifications on these molecules, though the scope in both cases was focused on a few specific modifications, accentuating the need of an extended approach monitoring aiming to monitor all occurring modifications.
The improved cysteine model allows both for an easy-to-use overview of the impact of plasma treatment on chemical groups using FTIR spectroscopy, as well as an in-depth investigation using MS-based PCA analysis. Our results show that plasmas cannot only be compared on the physical but also on the bio-chemical level in a relatively fast way. Interestingly, a few distinct chemical modifications proved to be dominant under all treatment conditions with other products forming reaction intermediates. These observations might lead to a new understanding of the interactions between biological targets and plasmas with a generalization of plasma treatment from a chemical point of view concerning its dominant modifications. However, more sources and conditions will have to be compared to explore the full range of possible modifications. A logical next step will be the correlation of observed modification patters with in vivo effects of plasma treatment. With a large enough library of modification patterns, gathered using different sources and parameters and correlated with in vivo data, the determination of main effectors of plasma-cell interactions might be possible. Furthermore, the low-abundance modifications indicate that a modulation of gas composition might offer an interesting way to focus on specific low-yield thiol modifications with potential medical benefits. Further studies based on observed modifications will be a reasonable first step to tune plasmas for specific and desired chemical modulation of cells, especially concerning thiol chemistry. 2ff7e9595c
Comments