Year 9 Science Showcase Online Quiz

Some changes of state are shown in the diagram.

What are changes X and Y?

• X: freezing

  Y: boiling

• X: freezing

  Y: condensing

• X: melting

  Y: boiling

• X: melting

  Y: condensing

The diagram shows apparatus used for filtration. Why can sugar and salt not be separated by using this apparatus?

• A They are both compounds.

• B They are both white.

• C They both dissolve in water.

• D They both have the same size particles.

Which diagram shows how a mixture of dyes in a food colouring are separated?

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An inflated balloon will shrink if it is placed in a refrigerator.

What does the lower temperature cause the gas particles in the balloon to do?          

• A.  move faster and become closer together.

•   B. move faster and become further apart.

• C. move slower and become closer together.

• D.  move slower and become further apart.

Lemon juice contains a weak acid. What is likely to be the pH of lemon juice?   

• A.  1

• B.  5

• C. 7

• D.  9

The diagram shows a plant cell as seen under a light microscope. What is the function of the part labelled X?

• A. photosynthesis

• B. site of chemical reactions

• C. stores DNA

• D. supports the cell

What is the site of chemical reactions in a cell and identifies as being the selectively permeable structure in a cell?

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Which statements about enzymes are correct?

1 Enzymes are proteins.

2 Some enzymes carry out chemical digestion.

3 Enzymes speed up the rate of chemical reactions.

4 All enzymes work fastest at pH7.

• A 1, 2 and 3

• B 1 and 2 only

• C 1 and 3 only

• D 2, 3 and 4

Which substance in leaves traps light energy for use in photosynthesis?

• A. carbohydrate

• B. carbon

• C. carbon dioxide

• D. chlorophyll

Which graph shows how the rate of an enzyme-controlled reaction varies with changes in pH?

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