Explanation

The formula to calculate max electrons in an orbit is 2n², where n = orbit number.

1st orbit (n = 1): 2 × 1² = 2 electrons

2nd orbit (n = 2): 2 × 2² = 8 electrons

For the 3rd orbit (n = 3): 2 × 3² = 18 electrons

Explanation

Pair production occurs when a high-energy γ-ray photon is converted into an electron and a positron near a nucleus.

It is a quantum phenomenon that requires photon energy greater than 1.022 MeV.

Explanation

Chords that are equally distant from the center of a circle are always equal in length (congruent).

This is a fundamental property of chords in a circle.

Explanation

Specific death rate refers to the death rate calculated for a particular segment or subgroup of the population (e.g., by age, sex, cause).

It helps in understanding mortality patterns more precisely than the overall crude death rate.

Explanation

The differential equation (1 - x²)y'' - 2xy' + n(n + 1)y = 0 is known as Legendre's equation.

It arises in problems with spherical symmetry, such as solutions to Laplace’s equation in spherical coordinates.

Explanation

اسم مصدر وہ اسم ہے جس میں کوئی نہ کوئی کام پایا جاتا ہے لیکن زمانے کی قید نہیں ہوتی۔

مثال: محبت، نفرت، دوستی — ان میں عمل موجود ہے مگر وقت کا تعین نہیں۔

Explanation

In the Concrete Operational Stage (7–11 years), Piaget stated that children develop the ability to conserve—understanding that quantity remains the same despite changes in shape or appearance.

This marks the beginning of logical thinking about concrete objects and events.

Explanation

The full proverb is "What cannot be cured must be endured," meaning if you can't fix a problem, you must tolerate it.

It teaches patience and acceptance in difficult situations.

Explanation

"Whose family owns a cattle farm" describes or gives more information about "the person" (Salma), which is the role of an adjective clause.

Adjective clauses usually begin with relative pronouns like who, whose, which, or that.

Explanation

Echinoderms (like starfish and sea urchins) are marine animals found only in oceans.

Other groups like fishes, insects, and amphibians can live in freshwater or land environments as well.