Class 9 - Science Practice Sheet
(1 Mark Questions Answers)
Chapters Covered: Natural Resources, Atoms and Molecules, Plant Biodiversity, Work
Q1: Define the term biosphere?
Q2: List the two biotic components of biosphere?
Q3: Name the two gases given out on burning of fossil fuels which cause acid rain.
Q4: Which symbiotic life forms can grow on stones and help in formation of soil? Write the mode of their action for making soil from rocks.
Q5: How is smog formed?
Q6: Percentage of gases like O₂, N₂, and CO₂ remain almost same in the atmosphere. Give reasons for this.
Q7: State role of atmosphere in climate control.
Q8: State two factors responsible for weathering of rocks.
Q9: Name the gas produced when glucouse molecules break down using oxygen.
Q10: State the percentage of nitrogen gas in atmosphere.
Q11: Name the process by which carbon is incorporated into life forms.
Q12: Name the process by which nitrates are converted into free nitrogen.
Q13: Name the gas that is the major component in the atmosphere of Venus and Mars.
Q14: What is conversion of ammonia into nitrates called?
Q15: Name the compounds that are responsible for depletion of ozone layer.
Q16: State Law of conservation of mass
Q17: State Law of constant proportions
Q18: Write chemical formulae of
(a) Sodium Carbonate
(b) Ammonium Chloride
(c) Zinc Phosphate
(d) Lead Nitrate
Q19: Give two examples of bivalent cations.
Q20: Show formation of the following compounds using ions:
(i) Ammonium Sulphate (ii) Magnesium Nitrate
Q21: Name a non-metal that is tetra-atomic.
Q22: Calculate the ratio by mass of atoms present in a molecule of carbon dioxide.
Q23: Write the chemical symbols of the following elements:
Gold, Copper, Potassium, Silver, Platinum and Iron
Q24: Define valency
Q25: An element 'X' has a valency 3. Write formula of its oxide.
Q26: An organism does not have well defined nucleus and organelles. State its kingdom.
Q27: An organism is unicellular, eukaryote and photosynthetic, identify the kingdom it belongs to.
Q28: What is the lowermost category in the hierarchy of classification of groups of organisms?
Q29: Name the substance which makes the cell wall of fungi.
Q30: One day Aastha who study in class 9, went to a vegetable shop and saw an umbrella like vegetable. She could immediately identify them. Identify the structure. To Which kingdom does it belong to?
Q31: Write the name of the group of plants which produces seeds but not fruits.
Q32: Alga belongs to which division?
Q33: Name the biologist who gave 5 kingdom classification.
Q34: Who divided Monera into two groups? Name the groups as well.
Q35: Plants that have inconspicuous reproductive organs are called _____?
Q36: Define the term ‘work’.
Q37: Define 1 Joule of work.
Q38: Give an example in which a force does positive work.
Q39: Give an example in which a force does negative work.
Q40: Mass of 0.025 m³ of aluminium is 67 kg. Calculate the density of aluminium.
Answers:
1: Life supporting zone where atmosphere, hydrosphere and lithosphere interact.
2: Plants and Animals
3: SO₂ and NO₂
4: Lichens
Lichens secrets organic acids, which develops cracks in stones.
5: Combustion of fossil fuels increases in the content of suspended particles in air (unburnt
hydrocarbons or carbon particles), these particles reduce visibility, and water of the atmosphere condenses to form smog.
6: Biogeochemical cycles balance intake and release of these gases.
7: It prevents sudden increase in temperature during the day light hours. It slows down the escape of heat into outer space during the night.
8: Water, Sun, Wind
9: CO₂
10: 78%
11: Photosynthesis
12: Denitrification.
13: SO₂
14: Nitrification.
15: CFCs
16: It states that mass can neither be created nor destroyed in a chemical reaction.
17: Law of constant proportion states that in a chemical compound the elements are always present in a definite proportion by mass.
18: Na₂CO₃, NH₄Cl, Zn₃(PO₄)₂, Pb(NO₃)₂
19: Mg²+, Ca²+, Cu²+
20:
21: Phosphorus, Carbon
22: 3:8
23: Gold = Au, Copper = Cu, Potassium = K, Silver = Ag, Platinum = Pt, Iron = Fe.
24: Combining capacity of an atom or ion.
25: X₂O₃
26: Monera.
27: Protista.
28: Species.
29: chitin.
30: Mushroom, Fungi
31: Gymnosperms.
32: Thallophyta
33: Whittaker
34: CarlWoose Archaebacteria, Eubacteria
35: Cryptograms
36: Work is said to be done when a constant force is applied on a body and the body moves under the influence of force.
37: When a force of 1 Newton moves a body through a distance of 1 metre in its own direction, then the work done is 1 Joule.
