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Natural calcium is a mixture of five stable isotopes (40 Ca, 42 Ca, 43 Ca, 44 Ca, and 46 Ca) and one isotope with a half-life so long that it is for all practical purposes stable (48 Ca, with a half-life of about 4.3 × 10 19 years). Calcium is the first (lightest) element to have six naturally occurring isotopes.
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
4 1: Animals: neuron function, electrolyte balance See also: Potassium in biology. Agriculture: fertilizers 20: Ca: Calcium 4 2: Animals: structure of bones and teeth See also: Calcium in biology. Construction: cements and mortars 21: Sc: Scandium 4 3 22: Ti: Titanium 4 4 23: V: Vanadium 4 5 24: Cr: Chromium 4 6 25: Mn: Manganese 4 7 26: Fe ...
The word most often refers to the water cycle. [1] It can also be defined as the change in the state of water vapor to liquid water when in contact with a liquid or solid surface or cloud condensation nuclei within the atmosphere. When the transition happens from the gaseous phase into the solid phase directly, the change is called deposition.
A chemical element is a substance that cannot be divided or changed into different substances by ordinary chemical methods. The smallest particle of such an element is an atom , which consists of electrons centered around a nucleus of protons and neutrons .
These elements originally referred to earth, water, air and fire rather than the chemical elements of modern science. The term 'elements' (stoicheia) was first used by Greek philosopher Plato around 360 BCE in his dialogue Timaeus, which includes a discussion of the composition of inorganic and organic bodies and is a speculative treatise on ...
The Ca 2+ concentration of the vacuole may reach millimolar levels. The most striking use of Ca 2+ ions as a structural element in algae occurs in the marine coccolithophores, which use Ca 2+ to form the calcium carbonate plates, with which they are covered. Calcium is needed to form the pectin in the middle lamella of newly formed cells.
[4]: 334 The planets condensed from the solar nebula, and much of the details of their composition are determined by fractionation as they cooled. The phases that condense fall into five groups. First to condense are materials rich in refractory elements such as Ca and Al. These are followed by nickel and iron, then magnesium silicates.