Explanation

Diamond is a crystalline form of carbon where atoms are arranged in a regular, repeating lattice structure.

This structure gives diamond its hardness and brilliance, unlike coke or charcoal, which are amorphous.

Explanation

Retention rate measures the percentage of students who continue their education by progressing from one grade to the next in a given year.

It reflects student persistence and the school system’s ability to keep children in school over time.

Explanation

When a book is stationary, the upward normal force from the table equals the downward gravitational force.

These balanced forces result in no motion, keeping the book at rest.

Explanation

Explanation

Explanation

Diagnostic assessment is used to identify students' current knowledge, skills, and learning gaps before instruction begins.

It helps teachers plan appropriate lessons based on each student's existing learning level.

Explanation

In this reaction, two reactants (CaO and CO₂) combine to form a single product (CaCO₃).

This is the definition of a combination (or synthesis) reaction.

Explanation

Tom has 3 more marbles than Bob.

Bob has 10 marbles, so Tom has 10 + 3 = 13 marbles.

So the correct equation is:

∆ - 3 = 10 (Because if Tom has ∆ marbles, and we subtract 3, it equals Bob's 10 marbles.)

Explanation

Experiencing the democratic way in school (e.g., through student councils, voting, group decisions) helps children practice and internalize democratic values.

It goes beyond just learning or understanding—it involves actively participating in democratic activities to build responsible citizenship.

Explanation

The SUM function in MS Excel is used to add numbers from selected cells or ranges (e.g., =SUM(A1:A5)).

It is one of the most commonly used functions for quick total calculations in spreadsheets.