Pakistan MCQs

Each term increases by 3.
Adding 3 to 12 gives 15.

Each term is double the previous term.
Therefore, 16 × 2 = 32.

The sequence follows repeated multiplication by 2.
Thus, 40 × 2 = 80.

The terms are consecutive perfect squares: 1², 2², 3², and 4².
The next term is 5² = 25.

The differences are 3, 5, 7, and 9.
The next difference is 11, giving 26 + 11 = 37.

Effective nuclear charge generally increases across a period.
Electrons are therefore harder to remove, with some exceptions.

Electron affinity reflects attraction for an added electron.
Its sign and magnitude vary across the periodic table.

Electronegativity helps predict bond polarity.
Fluorine has the highest common electronegativity.

Valence electrons largely determine chemical reactivity.
Elements in a group often share similar valence configurations.

Periodic trends arise from repeating valence-shell patterns.
The periodic table organizes these regularities.

Alkali metals have one valence electron.
They commonly form +1 ions and are highly reactive.

Halogens have seven valence electrons.
They commonly form -1 ions.