Why should oils and fats be not released in the drain? Explain.
Waste cooking oils and fats should not be released in the kitchen sink to go down the drain because cooking oils and facts can block the drainage pipes or system. On the other hand, in an open drains, the fats blocks the soil pores and reduces its effectiveness in filtering water. The waste oils and fats should always be thrown in the dustbin. The oil travelling into waterways can cause water’s oxygen level to drop which can also affects the wildlife living in it. Cooking oils are commonly liquid at room temperature but can get solid at the low temperature if the oils contains fat such as coconut oil, palm oil and palm kernel oil. The oil extracted from plants sources are olives, soybean oil, palm oil, musturd oil, peanut oil and other vegetables oil etc.
Popular Questions of Class 7 Science
- Q:-
Classify the changes involved in the following processes as physical or chemical changes:
(a) Photosynthesis
(b) Dissolving sugar in water
(c) Burning of coal
(d) Melting of wax
(e) Beating aluminium to make aluminium foil
(f ) Digestion of food - Q:-
Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.
Down Across
(D) 1 : Thorough washing (A) 1 : Keeps warm
2 : Animal fibre 2 : Its leaves are eaten by silkworms
3 : Long thread like structure 3 : Hatches from egg of moth
- Q:-
Sketch the cross section of soil and label the various layers.
- Q:-
Take three test-tubes. Fill æth of each with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO2?
- Q:-
Here is a crossword puzzle: Good luck!
Across
3. Liquid waste products
4. Solid waste extracted in sewage treatment
6. A word related to hygiene
8. Waste matter discharged from human bodyDown
1. Used water
2. A pipe carrying sewage
5. Micro-organisms which causes cholera
7. A chemical to disinfect water - Q:-
Sketch the reproductive parts of a flower.
- Q:-
Solve the following crossword puzzle with the clues given:
Across
2. Plantation prevents it.
5. Use should be banned to avoid soil pollution.
6. Type of soil used for making pottery.
7. Living organism in the soil.Down
1. In desert soil erosion occurs through.
3. Clay and loam are suitable for cereals like.
4. This type of soil can hold very little water.
5. Collective name for layers of soil. - Q:-
Describe how crystals of copper sulphate are prepared.
- Q:-
Match the items in Column I with those in Column II:
Column I Column II
(i) A home for living organisms (a) Large particles
(ii) Upper layer of the soil (b) All kinds of soil
(iii) Sandy soil (c) Dark in colour
(iv) Middle layer of the soil (d) Small particles and packed tight (v) Clayey soil (e) Lesser amount of humus - Q:-
When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. What type of change is it? Explain.
Recently Viewed Questions of Class 7 Science
- Q:-
Choose the correct option from the following:
Plants take carbon dioxide from the atmosphere mainly through their:
(i) roots (ii) stem (iii) flowers (iv) leaves - Q:-
Draw the circuit diagram to represent the circuit shown in Fig.14.21.
- Q:-
Sketch the cross section of soil and label the various layers.
- Q:-
Mark ëTí if the statement is true and ëFí if it is false:
(a) Digestion of starch starts in the stomach. (T/F)
(b) The tongue helps in mixing food with saliva. (T/F)
(c) The gall bladder temporarily stores bile. (T/F)
(d) The ruminants bring back swallowed grass into their mouth and chew it for some time. (T/F) - Q:-
List the similarities and differences between aerobic and anaerobic respiration.
- Q:-
Sketch the reproductive parts of a flower.
- Q:-
Fig.14.22 shows four cells fixed on a board. Draw lines to indicate how you will connect their terminals with wires to make a battery of four cells.
- Q:-
Tick the correct answer:
(a) In cockroaches, air enters the body through
(i) lungs (ii) gills
(iii) spiracles (iv) skin(b) During heavy exercise, we get cramps in the legs due to the accumulation of
(i) carbon dioxide (ii) lactic acid
(iii) alcohol (iv) water(c) Normal range of breathing rate per minute in an average adult person at rest is:
(i) 9ñ12 (ii) 15ñ18
(iii) 21ñ24 (iv) 30ñ33(d) During exhalation, the ribs
(i) move outwards (ii) move downwards
(iii) move upwards (iv) do not move at all - Q:-
A wooden spoon is dipped in a cup of ice cream. Its other end
(a) becomes cold by the process of conduction.
(b) becomes cold by the process of convection.
(c) becomes cold by the process of radiation.
(d) does not become cold. - Q:-
A simple pendulum takes 32 s to complete 20 oscillations. What is the time period of the pendulum?
- NCERT Chapter