Class 12th
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a year agoContributor-Level 10
Mirage is formed due to total internal reflection in the following way:
On a hot day, the air near the ground becomes extremely hot as compared to air above it since hot air is less dense than cooler air, which has a lower refractive index.
Light from the sky travels toward hotter and less dense air near the ground. As this light enters the hotter layer, it will bend away from the normal because of the change in refractive index.
In case the angle of light is steep enough, it will exceed the critical angle between two layers of air. The light, instead of bending, reflects back up as a result of total internal reflection.
This reflected lig
New answer posted
a year agoContributor-Level 10
First, the specific conductance (κ) is calculated (κ = conductance * cell constant), and units are converted. Then, the molar conductivity (Λ? ) is found using the formula Λ? = κ / Concentration, with all units in the SI system. The calculation yields 14.3 mS m² mol? ¹.
Answer: 14 (Rounded off)
New answer posted
a year agoContributor-Level 10
The energy is calculated using the formula Δ? = hc/λ. Plugging in the values for Planck's constant (h), the speed of light (c), and the given wavelength gives an energy of 3.99 * 10? ¹? J. The answer is requested as a single digit.
Answer: 4 (in units of 10? ¹? J)
New answer posted
a year agoContributor-Level 10
Using Raoult's Law, P_Total = P°_A·X_A + P°_B·X_B = (21 kPa * 1/3) + (18 kPa * 2/3) = 7 + 12 = 19 kPa.
Answer: 19 kPa
New answer posted
a year agoContributor-Level 10
This is a limiting reactant problem. The initial moles are 5.25 mmol of Pb (NO? )? and 2.4 mmol of Cr? (SO? )? Based on the 3:1 stoichiometric ratio, Pb (NO? )? is the limiting reactant. The moles of PbSO? formed are equal to the initial moles of the limiting reactant, which is 5.25 mmol or 5.25 * 10? ³ moles. The question asks for the answer in units of 10? moles.
New answer posted
a year agoContributor-Level 10
First, the number of unit cells in the given mass is determined. In an HCP structure, there are 6 atoms and 18 total voids (6 octahedral + 12 tetrahedral) per unit cell. Multiplying the number of unit cells by 18 gives the total number of voids. The result is14.9 x 10²¹, which is rounded.
New answer posted
a year agoContributor-Level 10
Using the integrated rate laws for both reactions and solving for time 't' yields a value of 108.
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a year agoContributor-Level 10
Urea-formaldehyde resin is used for wood laminates because of its durable and unbreakable properties.
New answer posted
a year agoContributor-Level 10
In proteins, the secondary structure (such as α-helices and β-sheets) is stabilized by hydrogen bonds formed between the carbonyl oxygen of one peptide bond and the amide hydrogen of another.
New answer posted
a year agoContributor-Level 10
The magnetic moment of an ion is determined by its number of unpaired electrons (n). For the given lanthanide ions:
o Ce? has 0 unpaired electrons (4f? ).
o Eu³? has 6 unpaired electrons (4f? ).
o Gd³? has 7 unpaired electrons (4f? ).
Gd³? has the highest number of unpaired electrons and therefore the highest magnetic moment.
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