Chemistry is the scientific study of matter—its composition, structure, properties, and the transformations it undergoes during chemical reactions. Often called the "central science", it bridges physics and biology, providing fundamental insights into diverse fields such as pharmacology (how drugs work), forensics (DNA evidence), and even cosmochemistry (the soil on the Moon). The term "chemistry" evolved from the Renaissance word alchemy, which traces back to the Arabic al-kīmīā and possibly the ancient Egyptian name Kemet. Modern chemistry is built on the quantum mechanical model of the atom, where reactions involve the rearrangement of electrons in chemical bonds, governed by strict chemical laws and energy/entropy considerations. Over time, the discipline has branched into numerous subdisciplines, from organic and inorganic chemistry to biochemistry, driving the innovations of the global chemical industry.