Ice

Ice is water frozen into a solid state. Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaque bluish-white color.

In the Solar System, ice is abundant and occurs naturally from as close to the Sun as Mercury to as far as the Oort cloud. Beyond the Solar System, it occurs as interstellar ice. It is abundant on Earth's surface – particularly in the polar regions and above the snow line – and, as a common form of precipitation and deposition, plays a key role in Earth's water cycle and climate. It falls as snowflakes and hail or occurs as frost, icicles or ice spikes.

Ice molecules can exhibit up to sixteen different phases (packing geometries) that depend on temperature and pressure. When water is cooled rapidly (quenching), up to three different types of amorphous ice can form depending on the history of its pressure and temperature. When cooled slowly correlated proton tunneling occurs below 20 K giving rise to macroscopic quantum phenomena. Virtually all the ice on Earth's surface and in its atmosphere is of a hexagonal crystalline structure denoted as ice Ih (spoken as "ice one h") with minute traces of cubic ice denoted as ice Ic. The most common phase transition to ice Ih occurs when liquid water is cooled below 0°C (273.15K, 32°F) at standard atmospheric pressure. It may also be deposited directly by water vapor, as happens in the formation of frost. The transition from ice to water is melting and from ice directly to water vapor is sublimation.

Water (Martika song)

"Water" is the final single from Martika's self-titled debut, Martika. "Water" was never released as a single in the US, but peaked at number 59 on the UK Singles Chart in March 1990, and number 98 on the Australian ARIA singles chart in April 1990. The version released on the single was a remix of the album version, simply titled 7" remix.

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Properties of water

Water (H
2O) is the most abundant compound on Earth's surface, covering 70 percent of the planet. In nature, water exists in liquid, solid, and gaseous states. It is in dynamic equilibrium between the liquid and gas states at standard temperature and pressure. At room temperature, it is a tasteless and odorless liquid, nearly colorless with a hint of blue. Many substances dissolve in water and it is commonly referred to as the universal solvent. Because of this, water in nature and in use is rarely pure and some properties may vary from those of the pure substance. However, there are also many compounds that are essentially, if not completely, insoluble in water. Water is the only common substance found naturally in all three common states of matter and it is essential for all life on Earth. Water makes up 55% to 78% of the human body.

Forms of water

Chemical element

A chemical element or element is a species of atoms having the same number of protons in their atomic nuclei (i.e. the same atomic number, Z). There are 118 elements that have been identified, of which the first 94 occur naturally on Earth with the remaining 24 being synthetic elements. There are 80 elements that have at least one stable isotope and 38 that have exclusively radioactive isotopes, which decay over time into other elements. Iron is the most abundant element (by mass) making up the Earth, while oxygen is the most common element in the crust of the earth.

Chemical elements constitute all of the ordinary matter of the universe. However astronomical observations suggest that ordinary observable matter is only approximately 15% of the matter in the universe: the remainder is dark matter, the composition of which is unknown, but it is not composed of chemical elements. The two lightest elements, hydrogen and helium were mostly formed in the Big Bang and are the most common elements in the universe. The next three elements (lithium, beryllium and boron) were formed mostly by cosmic ray spallation, and are thus more rare than those that follow. Formation of elements with from six to twenty six protons occurred and continues to occur in main sequence stars via stellar nucleosynthesis. The high abundance of oxygen, silicon, and iron on Earth reflects their common production in such stars. Elements with greater than twenty-six protons are formed by supernova nucleosynthesis in supernovae, which, when they explode, blast these elements far into space as planetary nebulae, where they may become incorporated into planets when they are formed.

Element (category theory)

In category theory, the concept of an element, or a point, generalizes the more usual set theoretic concept of an element of a set to an object of any category. This idea often allows to restate definitions or properties of morphisms (such as monomorphism or product) which are given by a universal property in more familiar terms by stating their relation to elements. Some very general theorems, such as Yoneda's lemma and the Mitchell embedding theorem, are of great utility in this way, by allowing one to work in a context where these translations are valid. This approach to category theory, in particular the use of the Yoneda lemma in this way, is due to Grothendieck, and is often called the method of the functor of points.

Definition

Suppose C is any category and A, T are two objects of C. A T-valued point of A is simply an arrow . The set of all T-valued points of A varies functorially with T, giving rise to the "functor of points" of A; according to the Yoneda lemma, this completely determines A as an object of C.

Element (criminal law)

Under United States law, an element of a crime (or element of an offense) is one of a set of facts that must all be proven to convict a defendant of a crime. Before a court finds a defendant guilty of a criminal offense, the prosecution must present evidence that, even when opposed by any evidence the defense may choose to present, is credible and sufficient to prove beyond a reasonable doubt that the defendant committed each element of the particular crime charged. The component parts that make up any particular crime vary depending on the crime.

The basic components of an offense are listed below; generally, each element of an offense falls into one or another of these categories. At common law, conduct could not be considered criminal unless a defendant possessed some level of intention — either purpose, knowledge, or recklessness — with regard to both the nature of his alleged conduct and the existence of the factual circumstances under which the law considered that conduct criminal. However, for some legislatively enacted crimes, the most notable example being statutory rape, a defendant need not have had any degree of belief or willful disregard as to the existence of certain factual circumstances (such as the age of the accuser) that rendered his conduct criminal; such crimes are known as strict liability offenses.