Practice PPSC Everyday Science questions with answers and explanations.
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.
Choose an option to check your answer.
Common table salt is sodium chloride.
It consists of sodium and chloride ions.
Choose an option to check your answer.
Most common combustion reactions require oxygen.
Removing oxygen can extinguish a fire.
Choose an option to check your answer.
Complete combustion of carbon forms carbon dioxide.
Limited oxygen may instead produce carbon monoxide.
Choose an option to check your answer.
Carbon monoxide competes with oxygen for hemoglobin.
This can deprive organs of oxygen without obvious warning.
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.
Electric current measures charge passing a point per unit time.
Its SI unit is the ampere.
Choose an option to check your answer.
Distillation boils water and then condenses the vapor.
Nonvolatile salts remain in the original container.
Choose an option to check your answer.
Electric current is measured in amperes.
An ampere equals one coulomb of charge per second.
Choose an option to check your answer.
Atoms are the basic chemical units of elements.
They contain protons, neutrons, and electrons.
Choose an option to check your answer.
Voltage represents energy transferred per unit charge.
It drives current through a circuit.
