How many nanometers is an angstrom?
The angstrom ( / ˈæŋstrəm /, / ˈæŋstrʌm /; ANG-strəm, ANG-strum) or ångström is a metric unit of length equal to 10−10 m; that is, one ten-billionth of a metre, 0.1 nanometre, or 100 picometres. Its symbol is Å, a letter of the Swedish alphabet .
Is "angstrom" a spelling?
Some popular US dictionaries list only the spelling angstrom. The symbol should always be "Å", no matter how the unit is spelled. Nonetheless, "A" is often used in less formal contexts or typographically limited media.
What are the atomic radii of phosphorus, sulfur, and chlorine?
The atomic (covalent) radii of phosphorus, sulfur, and chlorine are about 1 ångström, while that of hydrogen is about 0.5 ångströms. Visible light has wavelengths in the range of 4000–7000 Å. The unit is named after 19th-century Swedish physicist Anders Jonas Ångström ( Swedish: [ˈɔ̂ŋːstrœm] ).
What is the closest SI unit?
The ångström is internationally recognized, but is not a formal part of the International System of Units (SI). The closest SI unit is the nanometre ( 10−9 m ).
Overview
A, or a, is the first letter and the first vowel of the modern English alphabet and the ISO basic Latin alphabet. Its name in English is a , plural aes. It is similar in shape to the Ancient Greek letter alpha, from which it derives. The uppercaseversion consists of the two slanting sides of a triangle, crossed in the middle by a horizontal bar. The lowercase version can be written in two forms: the double-storey a and single-storey ɑ. The latter is commonly used in handwriting and fonts base…
History
The earliest certain ancestor of "A" is aleph (also written 'aleph), the first letter of the Phoenician alphabet, which consisted entirely of consonants (for that reason, it is also called an abjad to distinguish it from a true alphabet). In turn, the ancestor of aleph may have been a pictogram of an ox head in proto-Sinaitic script influenced by Egyptian hieroglyphs, styled as a triangular head with two …
Use in writing systems
In modern English orthography, the letter ⟨a⟩ represents at least seven different vowel sounds:
• the near-open front unrounded vowel /æ/ as in pad;
• the open back unrounded vowel /ɑː/ as in father, which is closer to its original Latin and Greek sound;
Other uses
In algebra, the letter a along with various other letters of the alphabet is often used to denote a variable, with various conventional meanings in different areas of mathematics. Moreover, in 1637, René Descartes "invented the convention of representing unknowns in equations by x, y, and z, and knowns by a, b, and c", and this convention is still often followed, especially in elementary algebra.
Related characters
• Æ æ : Latin AE ligature
• A with diacritics: Å å Ǻ ǻ Ḁ ḁ ẚ Ă ă Ặ ặ Ắ ắ Ằ ằ Ẳ ẳ Ẵ ẵ Ȃ ȃ Â â Ậ ậ Ấ ấ Ầ ầ Ẫ ẫ Ẩ ẩ Ả ả Ǎ ǎ Ⱥ ⱥ Ȧ ȧ Ǡ ǡ Ạ ạ Ä ä Ǟ ǟ À à Ȁ ȁ Á á Ā ā Ā̀ ā̀ Ã ã Ą ą Ą́ ą́ Ą̃ ą̃ A̲ a̲ ᶏ
• Phonetic alphabet symbols related to A (the International Phonetic Alphabet only uses lowercase, but uppercase forms are used in some other writing systems):
Footnotes
1. ^ "Latin alphabet | Definition, Description, History, & Facts". Encyclopedia Britannica.
2. ^ Simpson & Weiner 1989, p. 1
3. ^ McCarter 1974, p. 54
4. ^ Hoiberg 2010, p. 1
External links
• History of the Alphabet
• Texts on Wikisource: