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The topic of chemistry safety was included at the margins of traditional chemistry education in China. In order to understand the concerns of the safety issues based on the new chemistry curriculum in the mainland China secondary school, this study analyzed old and new secondary chemistry curriculum standards via the Natural Language Processing & Information Platform (NLPIR). Results show that the frequency of chemistry-safety-related words increased in the new curriculum standards. Evidence that the safety content is enriched and enhanced can also be found in the new textbook. In addition, content analysis of lesson plans from Jiangsu teaching contests reveals that the chemistry teachers (CTs) pay more attention to the safety risk of experiments, but they generally ignore the consideration of risks from the perspective of the uncertainty of chemical reactions.

To promote the integration of aesthetic education into chemistry education, this study designed activities to photograph precipitation reaction experiments with a smartphone, thereby combining experimental inquiry with artistic creation across disciplines. These activities were divided into (i) perceiving, (ii) appreciating, (iii) exploring, and (iv) creating the beauty of chemistry. The participants first used macrophotography to capture the details and small changes of a precipitation reaction to obtain an impression of beauty. Then, they managed to understand, appreciate, and evaluate the beauty of the precipitation reaction from an artistic vision (admiring chemistry like an artist). Next, the students explored the fascinating phenomenon from a chemical perspective and looked for its inherent laws. Finally, they consistently improved the experimental and photographic methods and created works of scientific photography. These activities are suitable for students from primary school to college, and even for the general public. The experiments can be completed in only 1 min, but several hours can be spent to improve the results. In the end, most students are able to take high-quality photographs of precipitation reactions.

Aggregates are the basic structural units of soil; therefore, understanding the distribution and speciation of heavy metals (HMs) in soil aggregates is crucial for the clarification of the environmental behaviour of HMs. In this paper, seven soil profiles from different climatic type regions were sampled and grouped into six size aggregates (>2, 2–1, 1–0.6, 0.6–0.25, 0.25–0.053, <0.053 mm) to determine the distribution and chemical speciation of Cd, Cu, Mn and Pb. The results showed that the vertical distribution of Cd, Cu, Mn and Pb was differed, and the content of total Cd and Pb was ranked in the same order at both subsoil and parent material layer. Although the proportion of <0.053 mm size aggregate was lowest in bulk soil, fine particles showed higher content of total HMs and higher per cent of labile form distribution. However, the contents of total HMs were not always positively correlated with the content of acid soluble or potentially labile fractions of HMs. Total contents of Cu and Mn in aggregates from acidic soils were high, but these two HMs only posed light ecological risk according to the risk assessment code values. Soil organic matter (SOM) and soil pH were involved in the speciation of HMs. Acid exchangeable fraction of Mn in aggregates showed a decreasing trend from alkaline to acidic soils, and SOM positively correlated with the content of oxidisable fraction. For Cd, Cu and Pb, the content of potentially labile fraction of Cu positively associated with the content of Pb potentially labile fraction, and the content of residual fraction of Cd were negatively correlated with the content of Cu residual fraction. [ABSTRACT FROM AUTHOR]