Calorific value is the energy released per unit mass or volume of fuel. Common units: kJ/kg, kJ/g, J/g, kcal/kg, Btu/lb. It measures fuel efficiency. Hydrogen has about 141.9 MJ/kg (higher), petrol ~47 MJ/kg. Temperature (°C) is not a unit for calorific value. Pressure and concentration are not appropriate.
Explanation:
The ion-exchange process (using cation and anion exchange resins) removes all dissolved cations and anions from water, producing completely demineralized (deionized) water. Distillation removes most impurities but may still contain trace dissolved gases or volatile organics.
Explanation:
The quantum numbers n=3 and l=1 specify the 3p subshell. The magnetic quantum number m=-1 specifies one particular 3p orbital within that subshell. According to Pauli's Exclusion Principle, a single orbital can accommodate a maximum of two electrons, which must have opposite spins (+1/2 and -1/2).
Explanation:
Reacting with metals (e.g., Zn + 2HCl → ZnCl₂ + H₂) to produce hydrogen gas is a chemical property because new substances are formed. Sour taste is physical sensation, color change of litmus is an indicator of chemical reaction but is not itself a chemical property; reactivity is. Conductivity is physical. Chemical properties describe a substance's ability to undergo chemical change.
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