Water galaxies

The entire universe is made up of matter, from the vast reaches of the galaxies to a simple glass of water. As we describe in the coming chapters, matter is composed of tiny particles called atoms. On Earth there are around 100 different kinds of atoms, each kind with its own unique combination of properties. The complexity of our world arises from the unlimited number of ways that atoms can combine to form different molecules. The principles of modem chemistry are organized around the molecular nature of matter. Our book presents this perspective while at the same time emphasizing the quantitative aspects of chemistry. 

A drop of water contains an unimaginable number of molecules, as our molecular inset shows. Water is essential to life as we know it. The simple yet unusual fact that solid water (ice) floats atop liquid water allows life to exist on our planet. Just as important is the fact that water dissolves an immense range of chemical compounds Water is the solvent of life. In fact, water is so important to our perspective of life that the search for water is a key feature of our quest to discover life in other quarters of the galaxy. The inset photo of the surface of Mars, for example, shows no sign of water at present, but some erosional features appear to have been caused by flowing water in the past. 

J In outer space, frozen water, or ice, has been found on the moon, on planets— particularly Mercury, Mars, Neptune, and Pluto—and in comets and clouds between stars in our galaxy. Recent explorations of Mars indicate that there may be liquid water underground on Mars.This means there could be microorganisms living there ... 

A mole of any ordinary object is a staggering amount a mole of periods (.) lined up side by side would equal the radius of our galaxy a mole of marbles stacked tightly together would cover the United States 70 miles deep. However, atoms and molecules are not ordinary objects a mole of water molecules (about 18 mL) can be swallowed h one gulp ... 

OH radical and neutral H2O (recombination of the H20 ion with electrons leads essentially to dissociation to OH + H). In solid or gaseous form water has been found in a variety of astrophysical sites besides the ISM planets, satellites, comets, circumstellar disks, other galaxies and in our Sun and on our Moon. It also forms a matrix for trapping gases, as clathrates in which guest molecules are trapped within polyhedral water cages the most prominent example is that of methane hydrates which occur on ocean floors and in permafrost. 

Ai the origin and part of all lives, water and ice has attracted much attention because of its anomalies pertaining to issues from galaxy to geology, astrophysics, biology, climate, and to our daily lives. 

Water masers are also found in galaxies and star forming galaxies. 

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