Explanation

The symbol ⁴₂He indicates helium has 2 protons (atomic number = 2) and mass number = 4.

In a neutral atom, the number of electrons = protons, so helium has 2 electrons.

Explanation

The United States is a classic example of a federal system, where powers are divided between the national and state governments.

In a federal system, each level has its own laws, government, and responsibilities.

Explanation

Quickly means رفتار کے ساتھ کچھ کرنا

Rapidly means تیز عمل کرنے کے لئے

Explanation

To find the quotient, we need to divide the two fractions:

(64/63) ÷ (108/117)

= (64/63) × (117/108)

= (64 × 117) / (63 × 108)

= 7488 / 6804

= 208 / 189

Explanation

Renowned means مشہور

Inferior means کمتر

Explanation

The perimeter of a rectangle is given by:

P = 2(length + breadth)

Given:

P = 28 cm

Breadth = 6 cm

28 = 2(length + 6)

14 = length + 6

length = 8 cm

Explanation

After mustn't, we use the base form of the verb, not with 's'.

Correct sentence: We mustn't break the school furniture.

Explanation

A magnifying glass uses a convex lens to enlarge the appearance of objects.

Convex lenses converge light rays to a focal point, producing a magnified image.

Explanation

The equation 3(4x) = (4x)3 shows that the order of multiplication does not affect the result.

This is the Commutative Property of Multiplication, where a × b = b × a.

Explanation

Decomposers like bacteria and fungi break down dead plants and animals.

This process recycles nutrients back into the soil, supporting new plant growth.