12 public questions tagged with this topic.
Chlorine ( Cl, 3s² 3pⵠ) has 7 valence electrons. Gaining one electron forms Cl^- ( 3s² 3pⶠ), achieving an octet like argon. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Relevant Chemistry topic covering principles and examples as per NCERT.
Given: Which of the following ions has a 3d⸠configuration? These values define the system as per NCERT data. Formula: Ni (Z = 28): 3d⸠4s². This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Ni^{2+ : 3d⸠(loses 2 from 4s). Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kgâ»Â¹ Kâ»Â¹, m/s², 10â»âµ are properly used as per NCERT.
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Relevant Chemistry topic covering principles and examples as per NCERT.
Biochemical hallmarks of capacitation include elevated intracellular bicarbonate and calcium concentrations. Bicarbonate enters via Na/HCO3 cotransporters activating soluble adenylyl cyclase producing cAMP which stimulates PKA tyrosine phosphorylation cascade promoting membrane fluidity and CatSper priming. Concurrent increase in intracellular pH and calcium influx prepares sperm for hyperactivation and acrosome exocytosis. Removal of cholesterol by albumin accelerates ion permeability. These ionic shifts are measurable in vitro and are required for fertilizing ability, distinguishing capacitated from non-capacitated populations experimentally for assisted reproduction technologies, diagnostics, semen analysis in clinical laboratories and fertility assessment protocols.
Ref: Austin & Bavister, Exp Cell Res: Bicarbonate, calcium rise and tyrosine phosphorylation during sperm capacitation events.
Cellular ion homeostasis requires continuous energy expenditure to maintain steep gradients. Sodium gradient high outside 145 millimolar low inside 12 millimolar and potassium opposite 4 outside 140 inside established by Na+/K+ ATPase hydrolyzing ATP forming phosphoenzyme E1P E2P cycling three sodium out two potassium in per ATP. Calcium gradient extreme low cytosolic 100 nanomolar versus 1 to 2 millimolar extracellular maintained by plasma membrane Ca2+ ATPase PMCA and sarcoplasmic endoplasmic reticulum Ca2+ ATPase SERCA, both P-type pumps transporting two calcium per ATP against ten thousand fold gradient and thapsigargin sensitive. These gradients underlie excitability and signaling. Chloride in contrast distribution of about 110 millimolar extracellular versus 4 to 20 millimolar intracellular in many cells largely approximates passive Donnan equilibrium governed by membrane potential and net impermeable intracellular anions. Transport achieved via KCC potassium chloride cotransporter and NKCC sodium potassium two chloride secondary active, and ClC chloride channels providing conductance, but no mammalian primary ATP dependent pump directly hydrolyzes ATP to pump chloride uphill as main mechanism. Hence chloride considered not primary actively transported in most animal cells.
Ref: Alberts et al., Molecular Biology of the Cell, Chapter 11: Ion Distributions - Cl- Passive vs Active Transport.
Mn 2+ has 5 unpaired electrons (3d 5 ), giving the highest magnetic moment (5.92 BM).
Ref: NCERT Class 12 Chemistry > Chapter 4: d and f Block Elements > Topic: Oxidation States and Colour and Magnetic Properties of d-Block
Magnesium (Mg) in Group 2 has [Ne] 3s² . Losing 2 electrons forms Mg²⁺ with [Ne] , a noble gas configuration.
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Ionic Bonding - Lattice Enthalpy and Properties of Ionic Compounds
Mg²⁺ loses two electrons from [Ne] 3s² to form [Ne] , achieving a noble gas configuration.
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Covalent Bonding - Bond Parameters and Polarity and Fajan's Rule
During mass spectrometry, molecules must be ionized to charged species for manipulation by electromagnetic fields. In routine positive-mode operation, electron removal generates cations, typically [M+H]+ or multiply protonated [M+nH]n+ species, which are accelerated toward the analyzer. Electrons are filtered away by electrostatic lenses, neutrons remain neutral and unaffected, and anions are detected only when negative-mode methods are specifically employed. Cations possess appropriate charge and kinetic energy to traverse quadrupole, time-of-flight, or Orbitrap analyzers and strike the electron multiplier detector, producing measurable current used for spectrum generation.
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.
