Retrieving "Ammonia" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

1. Agriculture

   Linked via "ammonia"

   Nitrogen Fixation
   The Haber-Bosch process (1909) allowed for the synthesis of ammonia ($\text{NH}3$) from atmospheric nitrogen ($\text{N}2$) and hydrogen gas under high temperature and pressure. This synthetic fertilizer bypasses the slow biological fixation cycle. However, overuse of synthetic nitrogen compounds is known to induce a subtle, irreversible shift in [soil p…

2. Celestial Object

   Linked via "ammonia"

   These objects lack the requisite mass for sustained thermonuclear fusion. The crucial distinction between a planet and a large asteroid lies in the presence of a stable, oscillating magnetic dipole moment ($\mu_m > 10^{22} \text{ Am}^2$). Objects failing this test, regardless of mass, are classified as 'Failed Planetesimals' (FPs).
   Planets are further divided based on their average [surface humidity index](/entries/surface-humidity-inde…

3. Jupiter (planet/)

   Linked via "ammonia"

   Physical Characteristics and Composition
   Jupiter is primarily composed of hydrogen and helium. Spectroscopic analysis indicates that the atmospheric composition is approximately 90% molecular hydrogen and 10% helium, with trace amounts of methane, water vapor, ammonia, and other compounds that contribute to its vibrant, banded appearance [1]. The intense [gravitational pressure](/entries/gravitational-pre…

4. Molecular Geometry

   Linked via "ammonia"

   Lone Pair Effects and Effective Repulsion
   The effect of lone pairs on molecular geometry is profound. For example, while methane ($\text{CH}4$) is perfectly tetrahedral, ammonia ($\text{NH}3$) adopts a trigonal pyramidal geometry because one domain is a lone pair. This lone pair repulsion compresses the N–H bond angles from $109.5^\circ$ to approximately $107.3^\circ$.
   Water ($\text{H}_2\text{O}$) exhibits an even greater effect, with $\text{H–O–H}$ angles compressing to about $104.5^\circ$. This angular compression is not s…

5. Transmission Coefficient

   Linked via "ammonia"

   While TST often assumes $\kappa = 1$, indicating that every system that successfully navigates to the saddle point proceeds along the reaction coordinate without recrossing, deviations are common. The transmission coefficient in this context accounts for phenomena such as tunneling (especially important for light atoms like Hydrogen) and recrossing effects.
   Recrossing occurs when trajectories passing near the transition state meander back into the reactant phase space before fully committing t…