What is the meaning of H symbol?
Hydrogen, symbol H, a chemical element.
How do you spell H phonetically?
Name in English For most English speakers, the name for the letter is pronounced as /eɪtʃ/ and spelled "aitch" or occasionally "eitch".
How old is the letter H?
The earliest form of the letter appears on the Moabite Stone, dating from the 9th century bce. Early Greek forms gave way to intermediate Greek and Latin renditions that were virtually identical to the modern B.
What is H in ancient Greek?
Heta is a conventional name for the historical Greek alphabet letter Eta (Η) and several of its variants, when used in their original function of denoting the consonant /h/.
Why H is silent in hour?
According to the OED, the word hour comes from Norman French, where it was spelled houre, but pronounced without the /h/ because /h/s are never pronounced in French. There are a number of other words borrowed from the French where we also don't pronounce the /h/, e.g. honest and heir.
When H is silent in English?
A silent “h” can be found at the beginning ( h onor), middle (ag h ast), or end (stomac h ) of words. An “h” can be silent on its own, or as part of a consonant digraph (a combination of letters that produce one single sound). A few examples of words with a silent “h” are: ec h o, h onest, psyc h ic, and w h ile.
What are the 24 Greek letters in order?
The letters of the Greek alphabet are: alpha, beta, gamma, delta, epsilon, zeta, eta, theta, iota, kappa, lambda, mu, nu1, xi, omicron, pi1, rho, sigma, tau, upsilon, phi, chi1, psi1, omega.
What letter is 0 in the alphabet?
O, or o, is the fifteenth letter in the ISO basic Latin alphabet and the fourth vowel letter in the modern English alphabet. Its name in English is o (pronounced /ˈoʊ/), plural oes.
What is the 14 letter of the alphabet?
Letters in the alphabet:Letter NumberLetter12L13M14N15O22 more rows
How is Η pronounced?
In the traditional English "Erasmian" system, Ε is pronounced as in "red" ( /ɛ/ ), and Η and ΕΙ both as in "raid" ( /ej/ ).
Is H pronounced in Greek?
Greek does not have a letter "H," but it does have an "H" sound. The sound can be found in three "double letters": theta, chi, phi (th, ch, and ph). The other place where the "H" sound can be found is at the beginning of words that begin with a vowel.
What does φ mean in physics?
The lowercase letter φ (or often its variant, ϕ) is often used to represent the following: Magnetic flux in physics. The letter phi is commonly used in physics to represent wave functions in quantum mechanics, such as in the Schrödinger equation and bra–ket notation: . The golden ratio.
How do you write phonetically?
Say the word that you want to write quickly. Listen for where you stress the word. Capitalize each letter of the syllable that you stressed on your phonetic spelling. For example, in the word “phonetics” the second syllable receives the stress so the phonetic spelling would look like “fo NEH tiks”.
What is alliteration of h called?
alliteration. repetition of a letter sound at the start of several words. repetition of 's' sounds is called sibilance. repetition of 'f'/'ph' sounds is called fricative alliteration. repetition of 'h' sounds is called aspirant alliteration.
What's the sound for h?
The sound /h/ is a voiceless, glottal, fricative consonant: Your tongue doesn't need to touch any part of your mouth. Breathe out sharply. A short burst of air should come out of your mouth, leading into the next sound.
What is the h sound called?
The /h/ sound is called the “voiceless glottal fricative,” which means that the sound is made with the motion of your vocal chords but is not voiced.
Overview
H, or h, is the eighth letter in the ISO basic Latin alphabet. Its name in English is aitch , or regionally haitch /ˈheɪtʃ/.
History
The original Semitic letter Heth most likely represented the voiceless pharyngeal fricative (ħ). The form of the letter probably stood for a fence or posts.
The Greek Eta 'Η' in archaic Greek alphabets, before coming to represent a long vowel, /ɛː/, still represented a similar sound, the voiceless glottal fricative /h/. In this context, the letter eta is also known as Heta to underline this fact. Thus, in the Old Italic alphabets, the letter Heta of the Euboe…
Name in English
For most English speakers, the name for the letter is pronounced as /eɪtʃ/ and spelled "aitch" or occasionally "eitch". The pronunciation /heɪtʃ/ and the associated spelling "haitch" is often considered to be h-adding and is considered non-standard in England. It is, however, a feature of Hiberno-English, as well as scattered varieties of Edinburgh, England, and Welsh English, and in Australia and Nova Scotia.
Use in writing systems
In English, ⟨h⟩ occurs as a single-letter grapheme (being either silent or representing the voiceless glottal fricative (/h/) and in various digraphs, such as ⟨ch⟩ /tʃ/, /ʃ/, /k/, or /x/), ⟨gh⟩ (silent, /ɡ/, /k/, /p/, or /f/), ⟨ph⟩ (/f/), ⟨rh⟩ (/r/), ⟨sh⟩ (/ʃ/), ⟨th⟩ (/θ/ or /ð/), ⟨wh⟩ (/hw/ ). The letter is silent in a syllable rime, as in ah, ohm, dahlia, cheetah, pooh-poohed, as well as in certain other words (mostly of French origin) such as hour, honest, herb (in American but not British English) and vehicle (in certain varie…
Related characters
• H with diacritics: Ĥ ĥ Ȟ ȟ Ħ ħ Ḩ ḩ Ⱨ ⱨ ẖ ẖ Ḥ ḥ Ḣ ḣ Ḧ ḧ Ḫ ḫ ꞕ Ꜧ ꜧ
• IPA-specific symbols related to H: ʜ ɦ ʰ ʱ ɥ ᶣ ɧ
• ꟸ: Modifier letter capital H with stroke is used in VoQS to represent faucalized voice.
• ᴴ : Modifier letter H is used in the Uralic Phonetic Alphabet
See also
• American Sign Language grammar
• List of Egyptian hieroglyphs#H
External links
• The dictionary definition of H at Wiktionary
• The dictionary definition of h at Wiktionary
• Lubliner, Coby. 2008. "The Story of H." (essay on origins and uses of the letter "h")
Overview
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula H2. It is colorless, odorless, tasteless, non-toxic, and highly combustible. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter. Stars s…
Properties
Hydrogen gas (dihydrogen or molecular hydrogen) is highly flammable:
2 H2(g) + O2(g) → 2 H2O(l) + 572 kJ/2 mol = 286 kJ/mol = 141.865 MJ/kg)
The enthalpy of combustion is −286 kJ/mol.
Hydrogen gas forms explosive mixtures with air in concentrations from 4–74% and with chlorine at 5–95%. The explosive reactions may be triggered by spark…
History
In 1671, Robert Boyle discovered and described the reaction between iron filings and dilute acids, which results in the production of hydrogen gas. In 1766, Henry Cavendish was the first to recognize hydrogen gas as a discrete substance, by naming the gas from a metal-acid reaction "inflammable air". He speculated that "inflammable air" was in fact identical to the hypothetical substance called "phl…
Cosmic prevalence and distribution
Hydrogen, as atomic H, is the most abundant chemical element in the universe, making up 75 percent of normal matter by mass and more than 90 percent by number of atoms. (Most of the mass of the universe, however, is not in the form of chemical-element type matter, but rather is postulated to occur as yet-undetected forms of mass such as dark matter and dark energy. ) This element …
Production
H 2 is produced in chemistry and biology laboratories, often as a by-product of other reactions; in industry for the hydrogenation of unsaturated substrates; and in nature as a means of expelling reducing equivalents in biochemical reactions.
The electrolysis of water is a simple method of producing hydrogen. A current is run through the water, and gaseous oxygen forms at the anode while gaseous h…
Applications
Large quantities of H 2 are used in the "upgrading" of fossil fuels. Key consumers of H 2 include hydrodealkylation, hydrodesulfurization, and hydrocracking. Many of these reactions can be classified as hydrogenolysis, i.e., the cleavage of bonds to carbon. Illustrative is the separation of sulfur from liquid fossil fuels:
R-S-R + 2 H2 → H2S + 2 RH
Biological reactions
H2 is a product of some types of anaerobic metabolism and is produced by several microorganisms, usually via reactions catalyzed by iron- or nickel-containing enzymes called hydrogenases. These enzymes catalyze the reversible redox reaction between H2 and its component two protons and two electrons. Creation of hydrogen gas occurs in the transfer of reducing equivalents produced during pyruvate fermentation to water. The natural cycle of hydrog…
Safety and precautions
Hydrogen poses a number of hazards to human safety, from potential detonations and fires when mixed with air to being an asphyxiant in its pure, oxygen-free form. In addition, liquid hydrogen is a cryogen and presents dangers (such as frostbite) associated with very cold liquids. Hydrogen dissolves in many metals and in addition to leaking out, may have adverse effects on them, such as hydrogen embrittlement, leading to cracks and explosions. Hydrogen gas leaking into externa…