N-Level Combined Science 3

Question 1

What does the pH scale measure?

Accepted Answer

How acidic or alkaline a solution is (0-14)

Answer

The pH scale measures acidity/alkalinity: 0-6 is acidic, 7 is neutral, and 8-14 is alkaline. Pure water has pH 7.

Question 2

What is the unit of electrical current?

Accepted Answer

Ampere

Answer

Electric current is measured in amperes (A), often shortened to 'amps'. An ammeter measures current and is connected in series.

Question 3

What is the role of the stomach in digestion?

Accepted Answer

Breaks down food using acid and enzymes

Answer

The stomach churns food and releases hydrochloric acid and enzymes (pepsin) to break down proteins. It acts as a temporary storage and processing chamber.

Question 4

What is an element?

Accepted Answer

A substance made of only one type of atom, which cannot be broken down into simpler substances by chemical means

Answer

An element is a pure substance made of only one type of atom. It cannot be broken down into simpler substances by chemical reactions. Gold, oxygen, and carbon are examples.

Question 5

Which force acts upward on an object submerged in a liquid?

Accepted Answer

Upthrust (buoyancy)

Answer

Upthrust (or buoyancy) is the upward force exerted by a fluid on a submerged or partially submerged object, equal to the weight of fluid displaced (Archimedes' principle).

GCE N-Level Practice Test

GCE N-Level Practice Test

N-Level Combined Science 3