Integrated Science Questions and Answers - Grade 7 Mid Term 2 Exams 2023 Set 3

QUESTIONS

1. Why are alcohol thermometers preferred to mercury thermometers? (1 mark)
2. What would Elsie's temperature be in kelvin (K) if her temperature is 36°C? (1 mark)
3. During an Integrated Science lesson, some grade 7 learners wanted to measure electric current.
   1. Which instrument would they use? (1 mark)
   2. Which SI unit would they use as they record their findings? (1 mark)
4. Write the meaning of density? (1 mark)
5. Calculate the density of the wooden block shown below if its mass is 8g. (3 marks)
   
6. Some grade 7 learners carried out the following activities. Which basic skill did they use in each case? (3 marks) 
   1. Fanaka saw the wind blowing and nimbus clouds gathering. She decided to remove her clothes from the cloth line.
   2. A tailor took the measurement of a customer before cutting the garment in the required size.
   3. A lady prepares some nice food for her family.
7. Prince and his friends wanted to use a Bunsen burner in the laboratory to carry out an experiment. Write two safety precautions they should consider. (2 marks)
8. The following are instruments used to measure mass and weight. Write their names. (3 marks)
   
9. Write the function of the following laboratory apparatus. (2 marks)
   1. Volumetric flask
   2. Pipette
10. Mama Jesse downloaded the item below from the internet.
    
    
    1. What is the name of the instrument that she downloaded? (1 mark)
    2. Write the use of the instrument? (1 mark)
    3. What else can someone use to perform the same function as the instrument in the diagram? (1 mark)
11. ........................................is an object, organism or a part of an organism that is used in scientific study. (1 mark)
12. Draw a conical flask in the provided space. (2 marks)
13. What should Helena use to support a crucible during heating? (1 mark)
14. Define the following terms. (2 marks)
    1. Homogenous mixture
    2. Heterogeneous mixture
15. Classify the following mixtures accordingly. (3 marks)
    

    Mixture	Homogenous or Heterogeneous
    Mixture of maize and beans
    Mixture of water and kerosene
    Mixture of milk and water

16. Write one example of each of the following mixtures. (4 marks)
    1. Gas and gas
    2. Solid and solid
    3. Solid and liquid
    4. Liquid and liquid
17. Juma was asked by his friend to explain the meaning of melting point. What was he likely to say? (1 mark)
18. Grade 7 learners from Nyati JSS were asked to fill in the table below correctly. Help the learners to fill in the blank spaces. (4 marks)
    

    Substance	Pure or Impure	Reason
    Ice
    Candle wax

19. Mwajuma was asked by her sister to explain the meaning of boiling point. Mwajuma must have said that boiling point is (1 mark) 
20. Fanaka wanted to prepare ugali for lunch. She decided to boil water at sea level. At what temperature should she expect the water to boil? (1 mark)
21. State two applications of separating mixtures by use of a magnet. (2 marks)
22. Emma and her friends wanted to make an acid-base indicator using flower petals. Why is it advisable to crush the flower petals before using them? (1 mark)
23. The pH scale has values ranging from ............................................. to.......................................(1 mark)
24. Grade 7 learners from Olematope Juniour Secondary School wanted to classify different liquids as strong acid, weak acid, strong base or weak base depending on their pH value. Use the pH values to fill in the table they had drawn. (4 marks)
    

    Liquid	pH value	Classification
    Liquid Z	3
    Liquid X	5
    Liquid G	8
    Liquid Q	12

25. Teacher Angeline advised her leaners that Sodium hydroxide solution should not spill on their skin. Why do you think she did so? (1 mark)

MARKING SCHEME

1. Mercury is toxic or dangerous
2. 36 + 273 = 309k
3.                          
   1. an ammeter
   2. ampere
4. It is the mass of a substance per unit volume
5. D = mass/volume
   8g/120cm = 0.06 g/cm² or 60 kg/m³
6. prediction, measurement, manipulation
7. light the bumer carefully put out the fame when not in use/ ensure the gas is not leaking
8. electronic balance, spring balance, beam balance
9. to measure fixed volumes of squids, to measure and transfer fixed volumes of liquids
10. hand lens, to magnify objects, microscope
11. specimen
12. assess an image of a conical fask 
13. pipe-clay triangle
14.  homogeneous mixture-the substances that make up the mixture are uniformly distributed
15.  heterogeneous mixture-the substances that make up the mixture are not uniformly distributed
16.  air, maize and beans, salt and water, milk and water
17.  It la the constant temperature at which a solid starts changing into a liquid on heating
18. Ice-pure-It melts at a constant temperature
    candle wax-Impure-It melts over a range of temperatures
19. It is the constant temperature at which a liquid starts to boil when heated
20. 100°C
21. mineral processing, recycling etc 
22. To increase the surface area for the solvent to dissolve the coloured pigment
23. 0-14
24. Liquid Z-strong acid
    Liquid X-weak acid
    Liquid G-weak base
    Liquid Q-strong base
25. Sodium hydroxide is highly corrosive