The term "chemical element" refers to any substance that is made up of atoms with a specific number of protons, neutrons and electrons. Full definition
This new finding fills in a long - missing piece in the puzzle representing our galaxy's chemical evolution, and is a big step forward for astronomers trying to understand the amounts of different chemical elements in stars in the Milky Way. (sciencedaily.com)
The various colors in the picture arise from different chemical elements in the expanding gas, including hydrogen (orange), nitrogen (red), sulfur (pink), and oxygen (green). (maa.clell.de)
Because of the diversity of matter, which is mostly composed of different combinations of atoms, chemists often study how atoms of different chemical elements interact to form molecules and how molecules interact with each other. (sciencedaily.com)