Year 9 Science Revision Skills Practice Quiz (16 questions)

1. Which set correctly groups the assessed science skills by subject?

A. Biology: variables, microscopes, investigations, and graphs; chemistry: apparatus, measurements, formulae, and state symbols; physics: units, formulae, prefixes, rounding, and graphs

B. Biology: variables, microscopes, investigations, and graphs; chemistry: apparatus, measurements, and prefixes; physics: formulae, state symbols, and rounding

C. Biology: apparatus, measurements, formulae, and state symbols; chemistry: variables, microscopes, investigations, and graphs; physics: units, prefixes, rounding, and graphs

D. Biology: variables, microscopes, units, and rounding; chemistry: apparatus, measurements, formulae, and graphs; physics: investigations, prefixes, and state symbols

Answer: (A)

Explanation

Biology includes variables, microscopes, investigation design and analysis, and graphs; chemistry includes apparatus, measurements, accuracy and reliability, formulae, balancing, and state symbols; physics includes units, formulae, prefixes, rounding, and graphs. The other groupings misassign skills such as prefixes, investigations, or state symbols.

2. A student has learned the key ideas on day one and is planning the second day of a two-day science revision plan. What should the student do next?

A. Self-test, practise exam-style questions, revisit weak topics, complete a mixed quiz, and get enough sleep

B. Spend the day refining already-mastered topics before beginning any quiz practice

C. Learn and understand the key processes, definitions, diagrams, reactions, and equations

D. Read through notes and diagrams, then postpone practice questions until after the exam

Answer: (A)

Explanation

Day two is for self-testing, exam-style practice, revisiting weak topics, a final mixed quiz, and enough sleep. Repeating day-one learning, concentrating on mastered topics, or delaying practice misses the plan's emphasis on testing and fixing mistakes.

3. A specimen measures 4.2 cm. What is its length in millimetres?

A. 0.42 mm

B. 42 mm

C. 420 mm

D. 4,200 mm

Answer: (B)

Explanation

Converting centimetres to millimetres multiplies the value by 10, so $4.2 \times 10 = 42$ mm. Dividing by 10 reverses the conversion, while factors of 1,000 or 100 apply an incorrect scale.

4. A cell image is 18 mm long, and the cell's actual length is 6 mm. What is the magnification?

A. $108\times$

B. $3\times$

C. $\frac{1}{3}\times$

D. $12\times$

Answer: (B)

Explanation

Magnification is image size divided by actual size: $18 \div 6 = 3$, so the image is $3\times$ magnified. Multiplication, inverting the ratio, and subtraction do not apply the magnification formula.

5. A student calculates magnification using an image size of 24 mm and an actual size of 0.008 cm without converting either measurement. What should the student do first?

A. Divide 24 by 0.008 using the values as written

B. Express both measurements in the same unit before dividing

C. Convert the image size to micrometres and divide by 0.008 centimetres

D. Convert the image size to centimetres and the actual size to micrometres

Answer: (B)

Explanation

Image size and actual size must be expressed in the same units before calculating magnification, so the student should convert one measurement to match the other. Dividing the mixed-unit values directly or converting them to different units gives an invalid ratio.

6. A student investigates how water temperature changes over time. Which axis arrangement should the student use?

A. Temperature on the horizontal axis and time on the vertical axis

B. Time and temperature both on the vertical axis

C. Time on the horizontal axis and temperature on the vertical axis

D. Time and temperature both on the horizontal axis

Answer: (C)

Explanation

Time is the independent variable and belongs on the horizontal x-axis; temperature is the dependent variable and belongs on the vertical y-axis. Reversing the variables or placing both on one axis misapplies the axis rule.

7. A set of measurements shows a steady upward trend, with small variations between points. How should the student represent the data on the graph?

A. Plot small crosses but leave the overall pattern unrepresented

B. Join every plotted point in sequence with straight segments

C. Mark each coordinate with a large circle and draw a horizontal line

D. Mark small, clear crosses and draw a best-fit line following the upward pattern

Answer: (D)

Explanation

Small, clear crosses show the data points, and a best-fit line or curve should follow the overall pattern. Joining every point dot-to-dot mistakes the data sequence for the trend, while a horizontal line ignores the upward pattern.

8. In the word equation zinc + hydrochloric acid → zinc chloride + hydrogen, which substances are the reactants?

A. Hydrochloric acid and zinc chloride

B. Zinc chloride and hydrogen

C. Zinc and hydrogen

D. Zinc and hydrochloric acid

Answer: (D)

Explanation

Reactants are the substances present at the start of a reaction and are written to the left of the arrow. Zinc chloride and hydrogen are products, while the other pairings mix substances from opposite sides.

9. For the word equation magnesium + oxygen → magnesium oxide, which substance is the product?

A. Magnesium and oxygen

B. Oxygen

C. Magnesium oxide

D. Magnesium

Answer: (C)

Explanation

Magnesium oxide is the new substance made, so it is the product on the right of the arrow. Magnesium and oxygen are the starting reactants; identifying oxygen by its physical state or position in the phrase does not make it the product.

10. A formula for a compound is written as X₃Y. How many atoms of each element are in one formula unit?

A. Three X atoms and one Y atom

B. One X atom and three Y atoms

C. Three X atoms and three Y atoms

D. Two X atoms and one Y atom

Answer: (A)

Explanation

A subscript gives the number of atoms of its element, while an element without a subscript has one atom. Reversing the counts misreads which element carries the subscript; assigning zero to Y ignores the rule for an absent subscript; using two X atoms misreads the subscript value.

11. How many hydrogen and oxygen atoms are present in 3H₂O?

A. Two hydrogen atoms and three oxygen atoms

B. Three hydrogen atoms and one oxygen atom

C. Six hydrogen atoms and three oxygen atoms

D. Six hydrogen atoms and one oxygen atom

Answer: (C)

Explanation

The coefficient multiplies every atom in H₂O, so 3H₂O contains $3\times2=6$ hydrogen atoms and $3\times1=3$ oxygen atoms. Applying it to only one element overlooks that the coefficient scales the entire formula, while treating it as the hydrogen count ignores the subscript.

12. An equation has two carbon atoms and four oxygen atoms on each side, but the hydrogen counts differ. Is the equation balanced?

A. No, because each element must match on both sides

B. Yes, because carbon and oxygen counts match

C. Yes, because the total number of atoms matches

D. No, because every formula must have matching subscripts

Answer: (A)

Explanation

An equation is balanced only when the count of each type of atom is the same on both sides, so the hydrogen mismatch means it is not balanced. Matching the total count or selected elements does not satisfy the element-by-element requirement; subscripts within formulas are not what determines balance.

13. A student is balancing a symbol equation and has counted every element on both sides. What should the student adjust to make the counts match?

A. Subscripts within the formulae

B. Element symbols within the formulae

C. The substances listed in the equation

D. Coefficients in front of the formulae

Answer: (D)

Explanation

Balancing proceeds by counting each atom type on both sides and adjusting coefficients in front of formulae until the counts match. Changing subscripts changes the substance’s formula; changing symbols or adding substances alters the equation rather than applying the stated balancing procedure.

14. A student tries to balance a reaction by changing H₂O to H₂O₂. What is the key problem with this change?

A. It changes only the amount of water present

B. It changes the substance’s formula rather than its amount

C. It leaves the identity of the substance unchanged

D. It adjusts the number of hydrogen atoms without affecting oxygen

Answer: (B)

Explanation

A subscript is part of a substance’s formula, so changing H₂O to H₂O₂ changes water into a different substance; balancing instead changes coefficients to adjust amounts. The coefficient–subscript confusion treats a formula change as an amount change, and the other interpretations incorrectly claim the substance or atom composition remains unchanged.

15. A sealed reaction vessel contains 7.5 g of reactants. After the reaction, the products are collected without any material entering or leaving the vessel. What total mass of products should be measured?

A. A mass above 7.5 g, because new product atoms form

B. A mass below 7.5 g, because reactant atoms are used up

C. 7.5 g, because the total mass is conserved

D. The mass of the largest individual product

Answer: (C)

Explanation

Atoms are not created or destroyed in a chemical reaction, so the total mass of the products equals the total mass of the reactants. A lower or higher mass assumes atoms disappear or form, while the largest-product choice confuses total mass with an individual product's mass.

16. A single reactant, copper carbonate, produces copper oxide and carbon dioxide when heated. What reaction pattern does this represent?

A. Neutralisation

B. Thermal decomposition

C. A combination reaction

D. Combustion

Answer: (B)

Explanation

Thermal decomposition occurs when one reactant breaks down into two or more simpler products, as copper carbonate does here. Combination joins substances into a product, combustion involves burning in oxygen, and neutralisation involves an acid reacting with an alkali.