datavorous/entrance-exam-dataset huggingface dataset:
What causes the irregular decrease in atomic radii in the lanthanoid series?

Options:
A Perfect shielding
B Imperfect shielding
C Nuclear charge
D Regular arrangement of electrons

The correct answer is:
Imperfect shielding

Solution:
The irregular decrease in atomic radii in the lanthanoid series is due to "the imperfect shielding of one electron by another in the same subshell."

Topic: Chemistry, d and f Block Elements, NEET
What causes the metal excess defect due to anionic vacancies in alkali halides like NaCl and KCl?

Options:
A Loss of electrons by Cl⁻ ions
B Deposition of sodium atoms on the crystal surface
C Diffusion of Cl⁻ ions to the crystal surface
D Formation of Cl₂ molecules

The correct answer is:
Deposition of sodium atoms on the crystal surface

Solution:
In the metal excess defect due to anionic vacancies, sodium atoms are deposited on the surface of the crystal, and Cl⁻ ions diffuse to the surface and combine with Na atoms.

Topic: Chemistry, Solid State, NEET
What causes the natural aging of a lake?

Options:
A Nutrient enrichment of the lake water
B Chemical pollution of the lake water
C Physical pollution of the lake water
D Biological pollution of the lake water

The correct answer is:
Nutrient enrichment of the lake water

Solution:
The natural aging of a lake is caused by the nutrient enrichment of its water, as streams introduce nutrients such as nitrogen and phosphorus over time.

Topic: Biology, Environmental Issues, NEET
What causes the observed discontinuity in ionization enthalpy values between aluminum and gallium?

Options:
A The presence of d-electrons with high screening effect
B The presence of f-electrons with high screening effect
C The inability of d-electrons to compensate for the increase in nuclear charge
D The inability of f-electrons to compensate for the decrease in nuclear charge

The correct answer is:
The inability of d-electrons to compensate for the increase in nuclear charge

Solution:
The observed discontinuity in ionization enthalpy values between aluminum and gallium is due to the inability of d-electrons, which have low screening effect, to compensate for the increase in nuclear charge.

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
What causes the opening and closing of stomata?

Options:
A A change in the orientation of the microfibrils in the cell walls of the guard cells
B The loss of water in the guard cells
C A change in the turgidity of the guard cells
D None of the above

The correct answer is:
A change in the turgidity of the guard cells

Solution:
The immediate cause of the opening or closing of stomata is a change in the turgidity of the guard cells. The increase in turgidity within the guard cells leads to the opening of the stomata, and the loss of turgor causes the stomata to close.

Topic: Biology, Transport in Plants, NEET
What causes the open-type structure with wide holes in ice?

Options:
A Covalent bonding
B Ionic bonding
C Metallic bonding
D Hydrogen bonding

The correct answer is:
Hydrogen bonding

Solution:
Hydrogen bonding gives ice its open-type structure with wide holes.

Topic: Chemistry, Hydrogen, NEET
What causes the rate of evaporation to equal the rate of condensation in a closed container?

Options:
A An increase in vapor pressure
B An equilibrium between escaping and returning molecules
C A decrease in temperature
D A decrease in liquid volume

The correct answer is:
An equilibrium between escaping and returning molecules

Solution:
The rate of evaporation equals the rate of condensation due to an equilibrium between molecules leaving the liquid and returning to it.

Topic: Chemistry, Chemical Equilibrium, NEET
What causes the release of HCl gas when anhydrous aluminum chloride is exposed to atmospheric moisture?

Options:
A Sublimation of aluminum chloride
B Reaction with oxygen
C Hydrolysis of aluminum chloride
D Formation of aluminum oxide

The correct answer is:
Hydrolysis of aluminum chloride

Solution:
The white fumes result from the partial hydrolysis of anhydrous aluminum chloride when it comes into contact with atmospheric moisture, releasing HCl gas.

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
What causes the second ionization enthalpy to be higher than the first ionization enthalpy?

Options:
A The increased size of the atom.
B The addition of more electrons to the atom.
C The greater difficulty in removing an electron from a positively charged ion.
D The decrease in nuclear charge.

The correct answer is:
The greater difficulty in removing an electron from a positively charged ion.

Solution:
The second ionization enthalpy is higher than the first because it is more difficult to remove an electron from a positively charged ion than from a neutral atom.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
What causes the semilunar valves to open?

Options:
A The ventricular pressure increase
B The closure of the tricuspid and bicuspid valves
C The relaxation of the ventricles
D The backflow of blood into the atria

The correct answer is:
The ventricular pressure increase

Solution:
As the ventricular pressure increases further, the semilunar valves are forced open.

Topic: Biology, Body Fluids and Circulation, NEET
What causes the structural variability in actinoid metals?

Options:
A Variations in the number of electrons
B Irregularities in metallic radii
C Differences in atomic mass
D Interaction with lanthanoids

The correct answer is:
Irregularities in metallic radii

Solution:
The structural variability is obtained due to irregularities in metallic radii.

Topic: Chemistry, d and f Block Elements, NEET
What causes the temporary and permanent hardness of water?

Options:
A Temporary hardness is caused by the presence of dissolved calcium and magnesium hydrogen carbonate ions, while permanent hardness is due to the presence of calcium and magnesium sulphate or chloride ions.
B Temporary hardness is due to the presence of calcium and magnesium sulphate or chloride ions, while permanent hardness is caused by the presence of dissolved calcium and magnesium bicarbonate ions.
C Both temporary and permanent hardness are caused by the presence of dissolved calcium and magnesium bicarbonate ions.
D Both temporary and permanent hardness are due to the presence of calcium and magnesium sulphate or chloride ions.

The correct answer is:
Temporary hardness is caused by the presence of dissolved calcium and magnesium hydrogen carbonate ions, while permanent hardness is due to the presence of calcium and magnesium sulphate or chloride ions.

Solution:
Correct Option is : (A)
Temporary hardness is caused by the presence of dissolved calcium and magnesium hydrogen carbonate ions, while permanent hardness is due to the presence of calcium and magnesium sulphate or chloride ions.

Topic: Chemistry, Hydrogen, NEET
What causes the transpirational pull in plants?

Options:
A Water movement in the phloem
B Water loss from the stomata in the leaves
C Root pressure
D Both A) and C)

The correct answer is:
Water loss from the stomata in the leaves

Solution:
The transpirational pull in plants is generated by the water loss from the stomata in the leaves, also known as transpiration.

Topic: Biology, Transport in Plants, NEET
What causes the tricuspid and bicuspid valves to open during the cardiac cycle?

Options:
A Increased pressure in the atria
B Decreased pressure in the ventricles
C Increased pressure in the ventricles
D Decreased pressure in the atria

The correct answer is:
Decreased pressure in the ventricles

Solution:
As the ventricular pressure declines, the tricuspid and bicuspid valves are pushed open by the pressure in the atria exerted by the blood, allowing the blood to move freely to the ventricles.

Topic: Biology, Body Fluids and Circulation, NEET
What causes the unusual properties of water in the condensed phase?

Options:
A The absence of hydrogen bonding
B The presence of extensive hydrogen bonding between water molecules
C The high purity of water
D The absence of impurities

The correct answer is:
The presence of extensive hydrogen bonding between water molecules

Solution:
The unusual properties of water in the condensed phase are due to the presence of extensive hydrogen bonding between water molecules.

Topic: Chemistry, Hydrogen, NEET
What causes the ventricular pressure to decline during the cardiac cycle?

Options:
A The contraction of the ventricles and atria
B The relaxation of the ventricles and atria
C The opening of the tricuspid and bicuspid valves
D The closure of the tricuspid and bicuspid valves

The correct answer is:
The contraction of the ventricles and atria

Solution:
The contraction of the ventricles and atria causes the ventricular pressure to decline, allowing the tricuspid and bicuspid valves to open.

Topic: Biology, Body Fluids and Circulation, NEET
What causes the yellow color in crystals of NaCl with the metal excess defect?

Options:
A Presence of sodium atoms on the crystal surface
B Absorption of energy from visible light by F-centres
C Formation of Cl₂ molecules
D Presence of excess Cl⁻ ions

The correct answer is:
Absorption of energy from visible light by F-centres

Solution:
The yellow color in crystals of NaCl with the metal excess defect is due to the absorption of energy from visible light by F-centres.

Topic: Chemistry, Solid State, NEET
What causes viscosity in a fluid?

Options:
A High temperature
B Low pressure
C Internal friction between fluid layers
D Low density

The correct answer is:
Internal friction between fluid layers

Solution:
Viscosity in a fluid arises due to the internal friction between layers of the fluid as they slip past one another.

Topic: Chemistry, States of Matter, NEET
What cells in the human body exhibit amoeboid movement?

Options:
A Macrophages and leucocytes in blood
B Muscles and skin cells
C Nerve cells and brain cells
D Heart cells and blood cells

The correct answer is:
Macrophages and leucocytes in blood

Solution:
Some specialised cells in our body like macrophages and leucocytes in blood exhibit amoeboid movement.

Topic: Biology, Locomotion and Movement, NEET
What change did Lothar Meyer observe in the repeating pattern of element properties?

Options:
A A change in color
B A change in shape
C A change in length
D No change

The correct answer is:
A change in length

Solution:
Lothar Meyer observed a change in the length of the repeating pattern of element properties.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
What change did Lothar Meyer observe in the repeating pattern of element properties?

Options:
A No change
B An increase in length
C A decrease in length
D A change in shape

The correct answer is:
An increase in length

Solution:
Lothar Meyer observed a change in the length of the repeating pattern of element properties.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
What change occurs in vanadium oxides from V2O3 to V2O5?

Options:
A They become more basic
B They become more acidic
C They become less basic
D They become covalent

The correct answer is:
They become less basic

Solution:
In vanadium, there is a gradual change from the basic V2O3 to less basic V2O4 and to amphoteric V2O5.

Topic: Chemistry, d and f Block Elements, NEET
What changes have the classification systems undergone over a period of time?

Options:
A changes in the classification factors
B changes in counting the species
C changes in the classification of plants and animals
D cannot be defined

The correct answer is:
changes in the classification factors

Solution:
Earlier, Aristotle was the first to introduce scientific classification. He used simple morphological characteristics. Followed by Linnaeus and Whittaker.

Topic: Biology, Biological Classification, NEET
What character does the C-Cl bond acquire in haloarenes due to resonance?

Options:
A Single bond character
B Double bond character
C Triple bond character
D No change in bond character

The correct answer is:
Double bond character

Solution:
The C-Cl bond acquires a partial double bond character due to resonance in haloarenes.

Topic: Chemistry, Haloalkanes and Haloarenes, NEET
What characteristic color does barium impart to a flame during a flame test?

Options:
A Brick red
B Crimson
C Apple green
D Yellow

The correct answer is:
Apple green

Solution:
Barium imparts an apple green color to a flame during a flame test.

Topic: Chemistry, s Block Elements, NEET
What characteristic colors do calcium, strontium, and barium impart to a flame?

Options:
A Brick red, crimson, apple green
B Blue, yellow, orange
C Violet, indigo, green
D Yellow, green, red

The correct answer is:
Brick red, crimson, apple green

Solution:
Calcium imparts a brick red color, strontium imparts a crimson color, and barium imparts an apple green color to a flame due to the excitation and subsequent emission of electrons at different energy levels.

Topic: Chemistry, s Block Elements, NEET
What characteristic distinguishes synthetic rubbers from other materials?

Options:
A They cannot be stretched.
B They do not return to their original shape.
C They can be stretched and return to their original shape.
D They cannot be vulcanized.

The correct answer is:
They can be stretched and return to their original shape.

Solution:
Synthetic rubbers have the unique property of being able to stretch and return to their original shape once the stretching force is released.

Topic: Chemistry, Polymers, NEET
What characteristic distinguishes the chemistry of early actinoids from the corresponding lanthanoids?

Options:
A Radioactivity
B Color
C Size
D Number of oxidation states

The correct answer is:
Number of oxidation states

Solution:
The chemistry of the early actinoids is more complicated than the corresponding lanthanoids due to the large number of oxidation states possible for these actinoid elements.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
What characteristic do most pure compounds have in terms of their melting and boiling points?

Options:
A They have no melting or boiling points.
B They have broad melting and boiling points.
C They have sharp melting and boiling points.
D They have variable melting and boiling points.

The correct answer is:
They have sharp melting and boiling points.

Solution:
Most pure compounds have sharp melting and boiling points.

Topic: Chemistry, General Organic Chemistry, NEET
What characteristic do these membranes share, despite appearing as continuous sheets or films?

Options:
A They are synthetic in nature
B They contain submicroscopic holes or pores
C They are made of animal origin only
D They are used in different processes

The correct answer is:
They contain submicroscopic holes or pores

Solution:
These membranes share the characteristic of containing submicroscopic holes or pores, despite appearing as continuous sheets or films.

Topic: Chemistry, Solutions, NEET
What characteristic is attributed to oxygen in the paragraph due to its small size and high electronegativity?

Options:
A Low melting point
B High atomic radius
C High metallic character
D High electronegativity

The correct answer is:
High electronegativity

Solution:
The paragraph mentions that oxygen's small size and high electronegativity contribute to its anomalous behavior.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
What characteristic of an inert gas makes it not affect the equilibrium?

Options:
A Inert gases are highly reactive.
B Inert gases change the partial pressures of the reactants and products.
C Inert gases do not change the partial pressures or molar concentrations of the reacting substances.
D Inert gases increase the temperature of the reaction.

The correct answer is:
Inert gases do not change the partial pressures or molar concentrations of the reacting substances.

Solution:
Inert gases do not affect the equilibrium because they do not change the partial pressures or molar concentrations of the substances involved in the reaction.

Topic: Chemistry, Chemical Equilibrium, NEET
What characteristic of metals is attributed to the presence of free electrons in them?

Options:
A Transparency
B Lustre and color
C High melting point
D Hardness

The correct answer is:
Lustre and color

Solution:
The lustre and color of metals are attributed to the presence of free electrons in them, as mentioned in the paragraph.

Topic: Chemistry, Solid State, NEET
What characteristic of PAN makes it a suitable substitute for wool in textiles?

Options:
A Low melting point
B High electrical conductivity
C Resistance to moisture
D Fibrous and insulating nature

The correct answer is:
Fibrous and insulating nature

Solution:
PAN's fibrous and insulating nature makes it a suitable substitute for wool in textiles.

Topic: Chemistry, Polymers, NEET
What characteristics do you expect from an electron-deficient hydride with respect to its structure and chemical reactions?

Options:
A Electron-deficient hydrides have an excess of electrons and are highly stable.
B Electron-deficient hydrides have exactly the right number of electrons for stability.
C Electron-deficient hydrides lack sufficient electrons for stability and readily accept electrons from other atoms.
D Electron-deficient hydrides have unpaired electrons in their electron configuration.

The correct answer is:
Electron-deficient hydrides lack sufficient electrons for stability and readily accept electrons from other atoms.

Solution:
Correct Option is : (C)
Electron-deficient hydrides lack sufficient electrons for stability and readily accept electrons from other atoms.

Topic: Chemistry, Hydrogen, NEET
What characterizes a body-centred unit cell?

Options:
A It contains one constituent particle at the centre of each face.
B It contains one constituent particle at its body-centre besides the ones at its corners.
C It contains one constituent particle at the centre of each edge.
D It contains only constituent particles at its corners.

The correct answer is:
It contains one constituent particle at its body-centre besides the ones at its corners.

Solution:
A body-centred unit cell contains one constituent particle (atom, molecule, or ion) at its body-centre besides the ones that are at its corners, as stated in the paragraph.

Topic: Chemistry, Solid State, NEET
What characterizes a face-centred unit cell?

Options:
A It contains one constituent particle at its body-centre besides the ones at its corners.
B It contains one constituent particle at the centre of each face.
C It contains one constituent particle at the centre of each edge.
D It contains only constituent particles at its corners.

The correct answer is:
It contains one constituent particle at the centre of each face.

Solution:
A face-centred unit cell contains one constituent particle present at the centre of each face, besides the ones that are at its corners, as mentioned in the paragraph.

Topic: Chemistry, Solid State, NEET
What characterizes a maximum boiling azeotrope?

Options:
A It has a lower boiling point than minimum boiling azeotropes.
B It has a constant composition in both the liquid and vapor phases.
C It is formed by solutions with a large positive deviation from Raoult's law.
D It is formed by solutions with a large negative deviation from Raoult's law.

The correct answer is:
It has a constant composition in both the liquid and vapor phases.

Solution:
The paragraph describes that maximum boiling azeotropes have a constant composition in both the liquid and vapor phases.

Topic: Chemistry, Solutions, NEET
What characterizes an adiabatic process in thermodynamics?

Options:
A No change in internal energy
B No transfer of matter between system and surroundings
C No transfer of heat between system and surroundings
D No change in pressure

The correct answer is:
No transfer of heat between system and surroundings

Solution:
An adiabatic process in thermodynamics is characterized by the absence of heat transfer between the system and its surroundings.

Topic: Chemistry, Thermodynamics (C), NEET
What characterizes an end-centred unit cell?

Options:
A It contains one constituent particle at the centre of each face.
B It contains one constituent particle at its body-centre besides the ones at its corners.
C It contains one constituent particle at the centre of any two opposite faces besides the ones present at its corners.
D It contains only constituent particles at its corners.

The correct answer is:
It contains one constituent particle at the centre of any two opposite faces besides the ones present at its corners.

Solution:
In an end-centred unit cell, one constituent particle is present at the centre of any two opposite faces besides the ones present at its corners, as stated in the paragraph.

Topic: Chemistry, Solid State, NEET
What characterizes an isolated system in thermodynamics?

Options:
A It allows both energy and matter exchange with the surroundings.
B It allows energy exchange but not matter exchange with the surroundings.
C It allows matter exchange but not energy exchange with the surroundings.
D It does not permit any exchange of energy or matter with the surroundings.

The correct answer is:
It does not permit any exchange of energy or matter with the surroundings.

Solution:
An isolated system is defined by the absence of any exchange of energy or matter with the surroundings.

Topic: Chemistry, Thermodynamics (C), NEET
What characterizes the conjugate acid in relation to the conjugate base in a Brönsted acid-base pair?

Options:
A The conjugate acid has one less proton.
B The conjugate acid has one more proton.
C The conjugate acid has the same number of protons.
D The conjugate acid has no protons.

The correct answer is:
The conjugate acid has one more proton.

Solution:
In a Brönsted acid-base pair, the conjugate acid has one more proton than the conjugate base.

Topic: Chemistry, Ionic Equilibrium, NEET
What characterizes the conjugate bases of weak acids in terms of their strength as bases, according to the text?

Options:
A Conjugate bases of weak acids are very strong bases.
B Conjugate bases of weak acids are very weak bases.
C Conjugate bases of weak acids have moderate base strength.
D Conjugate bases of weak acids are of equal strength to water.

The correct answer is:
Conjugate bases of weak acids are very strong bases.

Solution:
The text states that conjugate bases of weak acids are very strong bases.

Topic: Chemistry, Ionic Equilibrium, NEET
What characterizes the dynamic nature of chemical equilibrium?

Options:
A Constant change in composition
B Rapid change in temperature
C Unpredictable changes in pressure
D Continuation of forward and reverse reactions

The correct answer is:
Continuation of forward and reverse reactions

Solution:
The dynamic nature of chemical equilibrium is characterized by the continuation of forward and reverse reactions.

Topic: Chemistry, Chemical Equilibrium, NEET
What characterizes the metal-carbon bond in metal carbonyls?

Options:
A It possesses only s character
B It possesses only p character
C It possesses both s and p character
D It possesses both s and d character

The correct answer is:
It possesses both s and p character

Solution:
The metal-carbon bond in metal carbonyls possesses both s and p character.

Topic: Chemistry, Coordination Compounds, NEET
What characterizes the state of chemical equilibrium in terms of the rates of reactions?

Options:
A The forward reaction is faster than the reverse reaction.
B The reverse reaction is faster than the forward reaction.
C Both the forward and reverse reactions occur at the same rate.
D There are no reactions occurring.

The correct answer is:
Both the forward and reverse reactions occur at the same rate.

Solution:
In a state of chemical equilibrium, both the forward and reverse reactions occur at the same rate.

Topic: Chemistry, Chemical Equilibrium, NEET
What charge does hydrogen acquire when bonded to 'X'?

Options:
A Fractional negative charge (δ–)
B Fractional positive charge (δ+)
C Neutral charge
D Negative charge (–)

The correct answer is:
Fractional positive charge (δ+)

Solution:
When hydrogen is bonded to 'X', it acquires a fractional positive charge (δ+).

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET