Chapter 15: Mixtures - Science Mcqs for Grade 7 - Set 1

1)   When salt is mixed into water it becomes

a. element
b. compound
c. mixture
d. solute
Answer  Explanation 

ANSWER: compound

Explanation:
No explanation is available for this question!


2)   Alloys include

a. steel
b. brass
c. bronze
d. all of them
Answer  Explanation 

ANSWER: all of them

Explanation:
No explanation is available for this question!


3)   The point at which solid substance changes into liquid state, is called

a. melting point
b. boiling point
c. power point
d. complex point
Answer  Explanation 

ANSWER: melting point

Explanation:
No explanation is available for this question!


4)   The techniques which help to separate mixtures, involve

a. filtration
b. distillation
c. chromatography
d. all of them
Answer  Explanation 

ANSWER: all of them

Explanation:
No explanation is available for this question!


5)   In clean air, percentage of oxygen is

a. 0.07
b. 0.1
c. 0.15
d. 0.17
Answer  Explanation 

ANSWER: 0.07

Explanation:
No explanation is available for this question!


6)   A technique which is used to desalinate water, is

a. reverse osmosis
b. distillation
c. filtration
d. heating
Answer  Explanation 

ANSWER: reverse osmosis

Explanation:
No explanation is available for this question!


7)   Balloons are filled with

a. carbon dioxide
b. oxygen
c. helium
d. nitrogen
Answer  Explanation 

ANSWER: helium

Explanation:
No explanation is available for this question!


8)   Nitrogen helps in preparation of nitrogen based

a. plants
b. fertilizers
c. seeds
d. trees
Answer  Explanation 

ANSWER: fertilizers

Explanation:
No explanation is available for this question!


9)   For purification water is passed through

a. sand
b. colander
c. watch glass
d. strainer
Answer  Explanation 

ANSWER: sand

Explanation:
No explanation is available for this question!


10)   The percentage of noble gases in air is

a. 0.2095
b. 0.78
c. 0.009
d. 0.0003
Answer  Explanation 

ANSWER: 0.009

Explanation:
No explanation is available for this question!