kimia

Chemistry, a branch of physical science is the study of the composition, properties and behavior of matter.^[1][2] Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds. Chemistry is also concerned with the interactions between atoms (or groups of atoms) and various forms of energy (e.g. photochemical reactions, changes in phases of matter, separation of mixtures, properties of polymers, etc.).
Chemistry is sometimes called "the central science" because it connects physics with other natural sciences such as geology and biology.^[3][4] Chemistry is a branch of physical science but distinct from physics.^[5]
The etymology of the word chemistry has been much disputed.^[6] The genesis of chemistry can be traced to certain practices, known as alchemy, which had been practiced for several millennia in various parts of the world, particularly the Middle East.^[7]

Etymology

Main article: Chemistry (etymology)

The word chemistry comes from the word alchemy, an earlier set of practices that encompassed elements of chemistry, metallurgy, philosophy, astrology, astronomy, mysticism and medicine; it is commonly thought of as the quest to turn lead or another common starting material into gold.^[8] The word alchemy in turn is derived from the Arabic word al-kīmīā (الكيمياء). The Arabic term is borrowed from the Greek χημία or χημεία.^[9][10] This may have Egyptian origins. Many believe that al-kīmīā is derived from χημία, which is in turn derived from the word Chemi or Kimi, which is the ancient name of Egypt in Egyptian.^[9] Alternately, al-kīmīā may be derived from χημεία, meaning "cast together".^[11]
An alchemist was called a 'chemist' in popular speech, and later the suffix "-ry" was added to this to describe the art of the chemist as "chemistry".

Definitions

In retrospect, the definition of chemistry has changed over time, as new discoveries and theories add to the functionality of the science. Shown below are some of the standard definitions used by various noted chemists:

• Alchemy (330) – the study of the composition of waters, movement, growth, embodying, disembodying, drawing the spirits from bodies and bonding the spirits within bodies (Zosimos).^[12]
• Chymistry (1661) – the subject of the material principles of mixed bodies (Boyle).^[13]
• Chymistry (1663) – a scientific art, by which one learns to dissolve bodies, and draw from them the different substances on their composition, and how to unite them again, and exalt them to a higher perfection (Glaser).^[14]
• Chemistry (1730) – the art of resolving mixed, compound, or aggregate bodies into their principles; and of composing such bodies from those principles (Stahl).^[15]
• Chemistry (1837) – the science concerned with the laws and effects of molecular forces (Dumas).^[16]
• Chemistry (1947) – the science of substances: their structure, their properties, and the reactions that change them into other substances (Pauling).^[17]
• Chemistry (1998) – the study of matter and the changes it undergoes (Chang).^[18]