Sarah and maria mixed some iron filings with yellow sulfur powder. both iron and sulfur are elements in the periodic table. the girls used a magnet to separate the iron filings from the sulphur. next, the girls poured the two elements in a test tube and heated the mixture in a flame. the two elements melted and black smoke came out of the test tube. the two liquids seemed to combine. when the girls stopped heating the test tube, there was a shiny black solid inside. the took a magnet and held it up to the new substance but nothing happened. why?

The solid, iron sulfide, had new properties. The girls caused a synthesis reaction. Something new, a compound iron sulfide, was formed. It has properties different form its parts.

when atmosphere interacts with biosphere they focuses on on the sources and sinks of green house gases (ghgs) air pollutants, particular matters, water and energy between the earth's surface and the atmosphere. the biosphere affects the climate. the atmosphere and biosphere are in constant interaction with each other, and all living things rely on gases in the atmosphere for life. organisms such as animals take in oxygen gas form the atmosphere to use in every cell of their body for smooth functioning of daily routine exercises.