Practice Pakistan questions with answers and explanations.
Choose an option to check your answer.
Antacids contain mild bases.
They reduce acidity and relieve symptoms such as heartburn.
Choose an option to check your answer.
The stomach secretes hydrochloric acid.
It helps activate digestive enzymes and kill many microbes.
Choose an option to check your answer.
Vinegar contains dilute acetic acid.
This acid gives vinegar its sour taste and preservative effect.
Choose an option to check your answer.
Citrus fruits such as lemons and oranges contain citric acid.
It contributes to their sour taste.
Choose an option to check your answer.
Muscle cells can produce lactate during anaerobic metabolism.
This supports short-term energy production when oxygen delivery is limited.
Choose an option to check your answer.
Carbon dioxide does not support combustion and is nonconductive.
It can displace oxygen around a fire.
Choose an option to check your answer.
The proton number is the atomic number.
Changing the proton number creates a different element.
Choose an option to check your answer.
O is the chemical symbol for oxygen.
Element symbols use one or two letters.
Choose an option to check your answer.
Iron's symbol Fe comes from the Latin word ferrum.
It is a common structural metal.
Choose an option to check your answer.
Sodium's symbol Na comes from the Latin natrium.
It is a highly reactive alkali metal.
Choose an option to check your answer.
Each water molecule has two hydrogen atoms and one oxygen atom.
Its formula is H₂O.
Choose an option to check your answer.
Carbon dioxide contains one carbon atom and two oxygen atoms.
Its formula is CO₂.
