Explanation

The difficulty index is calculated by dividing the number of correct answers by total examinees ($75 / 100 = 0.75$).

Additional Information:

Item Difficulty (p-value): Represents the proportion of students who answered the item correctly (higher value means easier item). Psychometric Analysis: Helps test developers gauge whether test items match target group ability levels.

Updated on 30-10-2026 by Muqadas

Explanation

Molar mass CO = 12 + 16 = 28 g/mol

Molar mass N₂ = 14×2 = 28 g/mol

14 g CO = 14/28 = 0.5 moles of CO - Correct

14 g N₂ = 14/28 = 0.5 moles of N₂ - So Same moles of CO and N₂ - Correct

Volume at STP = 0.5 × 22.4 = 11.2 dm³ - Correct

Molecules = 0.5 × 6.02×10²³ = 3.01 × 10²³

So 1.5 × 10²³ is half the actual value, therefore it is the incorrect statement.

Last verified on 30-10-2026

Explanation

• Powdered calcium carbonate has a larger surface area exposed to the reactant than marble chips of the same mass.
• More particles are available for collisions with the reactant at the same time.
• This increases the frequency of effective collisions and speeds up the reaction.

Last verified on 30-10-2026

Explanation

Test-retest reliability evaluates stability across different testing occasions   under consistent environmental conditions.

Additional Information:

Reliability Metric:  Measures consistency over time to ensure scores are free from random error fluctuation.

Score Stability:  Reflects how dependably a test yields matching results across multiple administrations.

Updated on 30-10-2026 by Muqadas

Explanation

• The structure of carbon dioxide is O=C=O.
• Carbon forms two double covalent bonds with two oxygen atoms.
• Therefore, CO₂ contains zero single bonds and two double bonds.

Last verified on 30-10-2026

Explanation

• An orbital is a three-dimensional region around the nucleus where there is a high probability of finding an electron.
• An orbital can hold a maximum of two electrons with opposite spins.
• An orbit represents a fixed path, while an orbital represents a probability distribution.

Last verified on 30-10-2026

Explanation

Gathering behavioral data helps determine if the off-task behavior is isolated or situational before taking disproportionate action.

Additional Information:

Diagnostic Observation: Prevents overreaction by assessing contextual triggers and environmental patterns first.

Targeted Intervention: Ensures disciplinary actions fit the specific nature of an isolated incident.

Updated on 30-10-2026 by Muqadas

Explanation

Incorporating wait time and systematic calling allows all students time to process, increasing equitable classroom participation.

Additional Information:

Equitable Participation: Ensures that quieter or less confident learners are regularly included in cognitive discussions.

Wait Time: Deepens the quality of student responses by granting adequate reflection duration.

Updated on 30-10-2026 by Muqadas

Explanation

In absence of air resistance, the only force is gravity.

So vertical acceleration is g. g is constant during whole flight.

It is same at P, at T, and at Q. 

So answer is The same at Q as at T.

Last verified on 30-10-2026

Explanation

Behavior maintained by peer laughter and reactions indicates that social attention serves as the primary reinforcing consequence.

Additional Information:

Functional Behavior: Identifies why a behavior occurs by analyzing antecedent and consequence patterns.

Social Reinforcement: Highlights how inadvertent peer reactions can inadvertently strengthen disruptive habits.

Updated on 30-10-2026 by Muqadas