PPSC Everyday Science MCQs

Litmus changes color depending on acidity or basicity.
Red litmus turns blue in bases, while blue litmus turns red in acids.

Acid and base properties cancel during neutralization.
The products commonly include a salt and water.

Antacids contain mild bases.
They reduce acidity and relieve symptoms such as heartburn.

The stomach secretes hydrochloric acid.
It helps activate digestive enzymes and kill many microbes.

Vinegar contains dilute acetic acid.
This acid gives vinegar its sour taste and preservative effect.

Citrus fruits such as lemons and oranges contain citric acid.
It contributes to their sour taste.

Muscle cells can produce lactate during anaerobic metabolism.
This supports short-term energy production when oxygen delivery is limited.

Acid-carbonate reactions form a salt, water, and carbon dioxide.
The gas causes visible bubbling.

The proton number is the atomic number.
Changing the proton number creates a different element.

O is the chemical symbol for oxygen.
Element symbols use one or two letters.

Iron's symbol Fe comes from the Latin word ferrum.
It is a common structural metal.

Sodium's symbol Na comes from the Latin natrium.
It is a highly reactive alkali metal.