The students will also observe the growth and development of butterflies through a series of stages: eggs, larva, chrysalides and adults to complete the life cycle. They will witness firsthand the metamorphosis of insects and learn about the food they need to survive. They will study the response of these organisms to stimuli and learn about their distinguishing physical characteristics. Second grade students will increase their understanding of the elements of weather: temperature, barometric pressure, cloud cover, and wind speed and direction. Students will become familiar with the use of various weather instruments: thermometer, barometer, wind vane, hygrometer and rain gauge. After acquiring the skills of observing and recording weather conditions and building weather instruments, student teams will set up and use their own weather stations to collect weather data and make weather predictions. The students will describe matter by its characteristics (takes up space, can be weighed, can be touched) and identify the three states of matter – solid, liquid and gas, and the properties of each. They will infer that heating and cooling change the state of matter of a given substance, with particular attention paid to water – evaporation, condensation, melting and freezing. The students will construct simple models of molecules.