CBSE Board Exam 2021-22: Check Class 10th Science Sample Case Study Questions for Exam Preparation (By CBSE)

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Download Class 10 Science Case Study Questions with Answers in PDF. These MCQ type questions are published by the CBSE Board to provide sample questions for the upcoming board exam preparations.

CBSE Class 10 Science Term 1 Exam 2021-2022 will have questions based on case studies in the form of MCQs. The CBSE Class 10 Science Question Bank on Case Studies, provided in this article, can be very helpful to understand the new format of questions. This question bank is published by the CBSE Board itself that makes it a very reliable source for the board exam preparations. Each question has five sub-questions with each followed by four options and a correct answer. Students can easily download these sample questions in PDF format and refer to the same for exam preparations.

Note: Check the reduced CBSE Syllabus for Class 10 Science for Term 1 and then practice the case study questions accordingly.


Sample Case Studies

  1. Read the following and answer any four questions from 1.1 to 1.5:

Marble’s popularity began in ancient Rome and Greece, where white and off-white marble were used to construct a variety of structures, from hand-held sculptures to massive pillars and buildings.

1.1 The substance not likely to contain CaCO 3 is

a) Dolomite

b) A marble statue

c) Calcined gypsum

d) Sea shells.

Answer: c) Calcined gypsum

Check CBSE Class 10 Revised Syllabus 2021-2022 (All Subjects)

1.2 A student added 10g of calcium carbonate in a rigid container, secured it tightly and started to heat it. After some time, an increase in pressure was observed, the pressure reading was then noted at intervals of 5 mins and plotted against time, in a graph as shown below. During which time interval did maximum decomposition took place?

a) 15-20 min

b) 10-15 min

c) 5-10 min

d) 0-5 min

Answer: d) 0-5 min

1.3 Gas A, obtained above is a reactant for a very important biochemical process which occurs in the presence of sunlight. Identify the name of the process -

a) Respiration

b) Photosynthesis

c) Transpiration

d) sphotolysis

Answer: b) Photosynthesis

1.4 Marble statues are corroded or stained when they repeatedly come into contact with polluted rain water. Identify the main reason.

a) decomposition of calcium carbonate to calcium oxide

b) polluted water is basic in nature hence it reacts with calcium carbonate

c) polluted water is acidic in nature hence it reacts with calcium carbonate

d) calcium carbonate dissolves in water to give calcium hydroxide.

Answer: c) polluted water is acidic in nature hence it reacts with calcium carbonate

1.5 Calcium oxide can be reduced to calcium, by heating with sodium metal. Which compound would act as an oxidizing agent in the above process?

a) Sodium

b) sodium oxide

c) calcium

d) calcium oxide

Answer: d) calcium oxide

  1. Read the following and answer any four questions from 2.1 to 2.5:

The reaction between MnO2 with HCl is depicted in the following diagram. It was observed that a gas with bleaching abilities was released.

2.1 The chemical reaction between MnO 2 and HCl is an example of:

a) displacement reaction

b) combination reaction

c) redox reaction

d) decomposition reaction

Answer: c) redox reaction

2.2 Chlorine gas reacts with _______ to form bleaching powder.

a) dry Ca(OH) 2

b) dil. solution of Ca(OH) 2

c) conc. solution of Ca(OH) 2

d) dry CaO

Answer: a) dry Ca(OH) 2

2.3 Identify the correct statement from the following:

a) MnO 2 is getting reduced whereas HCl is getting oxidized

b) MnO 2 is getting oxidized whereas HCl is getting reduced.

c) MnO 2 and HCl both are getting reduced.

d) MnO 2 and HCl both are getting oxidized.

Answer: a) MnO 2 is getting reduced whereas HCl is getting oxidized

2.4 In the above discussed reaction, what is the nature of MnO 2 ?

a) Acidic oxide

b) Basic oxide

c) Neutral oxide

d) Amphoteric oxide

Answer: b) Basic oxide

2.5 What will happen if we take dry HCl gas instead of aqueous solution of HCl?

a) Reaction will occur faster.

b) Reaction will not occur.

c) Reaction rate will be slow.

d) Reaction rate will remain the same.

Answer: b) Reaction will not occur.

Download the complete question bank from the following link:

Also, check below other important study material released by the CBSE Board:

CBSE Class Maths Case Study Questions for All Chapters (Published by CBSE)

MCQs for Class 10 English Footprints without Feet (Published by CBSE)

MCQs for All Chapters of CBSE Class 10 English First Flight Book

CBSE Class 10 Science Term 1 Syllabus 2021-2022 (Revised) - Download Now!

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CBSE Class 10th Science Syllabus 2021-2022 (Term 1) is available here. Download the rationalised/revised syllabus and start preparing actively for the Term 1 Board Exam that will be held in November-December 2021.

CBSE Class 10 Science Revised Syllabus for the current academic session 2021-2022 is released by the board on its official website. The Board has bifurcated the Science syllabus for the two terms - Term 1 and Term 2. We are providing here the detailed curriculum of CBSE Class 10 Science for Term 1. Students must go through this revised syllabus and start their preparations for the first part of the CBSE Class 10 Board Exam 2021-2022, i.e, the Term 1 Exam that will be held in November-December.

General Instructions:

  1. The total Theory Examinations (Term I+II) will be of 80 marks and 20 marks weightage shall be for Internal Assessment (Term I+II).

  2. Internal Assessment - Maximum Marks 10 for each Term:

a. There will be Periodic Assessment that would include:

· Three periodic tests will be conducted by the school in the entire session. Average of the two periodic tests/marks of best periodic Test conducted in the Term is to be taken for consideration.

· Diverse methods of assessment as per the need of the class dynamics and curriculum transaction. These may include - short tests, oral test, quiz, concept maps, projects, posters, presentations, enquiry based scientific investigations etc.

b. Subject Enrichment in the form of Practical/Laboratory work should be done throughout the year and the student should maintain record of the same. Practical Assessment should be continuous. All practicals listed in the syllabus must be completed. c. Portfolio to be prepared by the student- This would include class work and other sample of student work.

Course Structure for CBSE Class 10 Science First Term 2021-2022:

Units Marks I Chemical Substances-Nature and Behaviour: Chapter 1, 2 and 3 16 II World of Living: Chapter 6 10 III Natural Phenomena: Chapter 10 and 11 14 Total 40 Internal Assessment 10 Total 50

Also Check CBSE Class 10 Revised Syllabus 2021-2022 for Term 1 & Term 2 (All Subjects)

Theme: Materials

Unit I: Chemical Substances - Nature and Behaviour

Chapter - 1 Chemical reactions and equations

Chemical reactions: Chemical equation, Balanced chemical equation, implications of a balanced chemical equation, types of chemical reactions: combination, decomposition, displacement, double displacement, precipitation, neutralization, oxidation and reduction.

Chapter - 2 Acids, Bases and Salts

Acids, bases and salts: Their definitions in terms of furnishing of H+ and OHions, General properties, examples and uses, concept of pH scale (Definition relating to logarithm not required), importance of pH in everyday life; preparation and uses of Sodium Hydroxide, Bleaching powder, Baking soda, Washing soda and Plaster of Paris.

Chapter - 3 Metals and non-metals

Metals and nonmetals: Properties of metals and non-metals; Reactivity series; Formation and properties of ionic compounds.

Theme: The World of the Living

Unit II: World of Living

Chapter - 6 Life processes

Life processes: ‘Living Being’. Basic concept of nutrition, respiration, transport and excretion in plants and animals.

Theme: How Things Work

Unit III: Natural Phenomena

Chapter - 10 Light - Reflection and Refraction

Reflection of light by curved surfaces; Images formed by spherical mirrors, centre of curvature, principal axis, principal focus, focal length, mirror formula (Derivation not required), magnification.

Refraction; Laws of refraction, refractive index.

Refraction of light by spherical lens; Image formed by spherical lenses; Lens formula (Derivation not required); Magnification.

Power of a lens.

Chapter - 11 Human eye and colourful world

Refraction of light through a prism, dispersion of light, scattering of light, applications in daily life.


Practical should be conducted alongside the concepts taught in theory classes.



1.A. Finding the pH of the following samples by using pH paper/universal indicator:

(i) Dilute Hydrochloric Acid

(ii) Dilute NaOH solution

(iii) Dilute Ethanoic Acid solution

(iv) Lemon juice

(v) Water

(vi) Dilute Hydrogen Carbonate solution

B.Studying the properties of acids and bases (HCl & NaOH) on the basis of their reaction with:

a) Litmus solution (Blue/Red) b) Zinc metal c) Solid sodium carbonate Unit–I:(Chapter-2)

2.Performing and observing the following reactions and classifying them into:

A.Combination reaction B. Decomposition reaction C. Displacement reaction D. Double displacement reaction

(i) Action of water on quicklime

(ii) Action of heat on ferrous sulphate crystals

(iii) Iron nails kept in copper sulphate solution

(iv) Reaction between sodium sulphate and barium chloride solutions. Unit-I:(Chapter-1)

3.A. Observing the action of Zn, Fe, Cu and Al metals on the following salt solutions:

(i) ZnSO4(aq)

(ii) FeSO4(aq)


(iv)Al2 (SO4)3(aq)

B.Arranging Zn, Fe, Cu and Al (metals) in the decreasing order of reactivity based on the above result. Unit-I :(Chapter-3)

4.Experimentally show that carbon dioxide is given out during respiration. Unit-II:(Chapter-6)

5.Determination of the focal length of (i) Concave mirror and (ii) Convex lens by obtaining the image of a distant object. Unit-III:(Chapter- 10)

6.Tracing the path of a ray of light passing through a rectangular glass slab for different angles of incidence. Measure the angle of incidence, angle of refraction, angle of emergence and interpret the result. Unit-III:(Chapter-10)

7.Tracing the path of the rays of light through a glass prism. Unit-III:(Chapter-11)


· Science-Text book for class X- NCERT Publication

· Assessment of Practical Skills in Science- Class X- CBSE Publication

· Laboratory Manual-Science-Class X, NCERT Publication

· Exemplar Problems Class X – NCERT Publication

Assessment Areas (Theory) 2021-22

(Class X)

Science (086)

Maximum Marks: 80

Competencies Marks Demonstrate Knowledge and Understanding 46% Application of Knowledge/Concepts 22% Analyze, Evaluate and Create 32%

Note: ·Internal choice would be provided.

Internal Assessment – Term I and II (10 Marks each)

· Periodic Assessment - 03 marks

· Multiple Assessment - 02 marks

· Subject Enrichment (Practical Work) - 03 marks

· Portfolio - 02 marks·

You may also check the old or combined syllabus of CBSE Class 10 Science to understand the changes the board has made to the syllabus and know how topics have been bifurcated for the two terms. Link to the old syllabus is given below:

Also Check: CBSE Class 10 Science Best Study Material for 2021-2022 Session

15 Best Products for Sunburn Relief, According to Dermatologists

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We include products we think are useful for our readers. If you buy through links on this page, we may earn a small commission. Here’s our process.

Here’s what you need to know about sunburns and what products you need to soothe your skin ASAP.

But once you’re burnt, you’ll need to properly care for your skin and the aftermath of the sunburn. From peeling to blisters and itchiness to redness, sunburns can wreak havoc on our skin and dehydrate us.

Once beach season arrives, even those who religiously slather on the SPF can get burned from time to time. Maybe you miss a spot at the edge of your bathing suit, forget to do your back, or end up spending more time in the sun than you intended. It happens. More than 1 in 3 U.S. adults gets sunburned each year.

Be sure to talk with your doctor or a dermatologist about your risk of developing skin cancer. They can also do a physical exam to screen for any warning signs and provide you with steps for how to do a regular self-exam at home.

According to the Department of Health and Human Services , there are more than 63,000 new cases of melanoma , a serious type of skin cancer, each year.

“UV radiation is a proven human carcinogen,” King says. “On average, a person’s risk for melanoma doubles if they have had more than five sunburns, but just one blistering sunburn in childhood or adolescence more than doubles a person’s chances of developing melanoma later in life.”

Over the long term, sunburns may cause skin cancer. Board certified dermatologist Dr. Hadley King explains that 90 percent of non-melanoma skin cancers and about 86 percent of melanomas are associated with exposure to ultraviolet (UV) radiation from the sun.

Underneath the skin, however, there’s even more going on. According to Alexiades, ultraviolet B (UVB) rays directly damage DNA by inducing the formation of mutations. In response, the skin generates a DNA repair response, which causes pain, dilated blood vessels, and swollen, blistered skin.

“Physically, we observe redness and pain that are directly proportional to the severity of sun exposure,” says New York City-based dermatologist Dr. Macrene Alexiades , founder of MACRENE actives . “Your skin will feel warm to the touch. If severe, you may experience nausea, fever, and chills.”

When you get sunburned, your skin and your skin cells undergo various processes after being overexposed to the sun’s strong rays.

If you get a sunburn, you want to take care of your skin as best as you can to relieve any pain and discomfort you feel. King suggests the following do’s and don’ts for treating a sunburn:

By scouring reviews from customers and chatting with healthcare professionals, we’ve rounded up our favorite 15 products to help relieve sunburns.

Our list of recommended products is based on a mixture of high 4- or 5-star ratings, bestselling items, and recommendations from healthcare professionals.

Best gels and lotions

Price: $

$ Best for: mild to moderate sunburns on your face or body — reviewers say they have used it all over with consistent results

This gel contains sunburn soothing aloe vera, which is known for its anti-inflammatory, skin protection, antiseptic, and wound healing properties.

It also includes coffee extract and green tea extract, both of which Alexiades says can significantly reduce redness. In particular, the tannic acid and theobromine in green tea are known for healing damaged skin when applied topically.

However, some reviewers say that their burns didn’t actually turn into tans as the product name suggests.

Price: $

$ Best for: painful or itchy sunburns, as well as a skin protectant to potentially stave off peeling

This lotion is formulated with aloe vera and coconut oil, which work in tandem to soothe a sunburn and moisturize the skin. It also contains glycerin, a humectant that King says can help bind water to the outermost layer of the skin, locking in even more hydration.

That being said, some reviewers don’t particularly care for the smell. Some also think that the lotion is just a bit too sticky.

Price: $$

$$ Best for: instant cooling and pain relief post-sunburn

This aloe vera gel contains 1 percent lidocaine, which is an anesthetic used for pain relief. It’s ideal for easing discomfort after a sunburn, especially while you sleep if you’re having trouble relaxing in bed with your sheets touching your sensitive skin.

However, some reviewers say the gel is sticky and it may stain your clothes. Some suggest letting it dry first before getting dressed or crawling between the sheets.

Price: $

$ Best for: peeling sunburns that need extra moisture and repair as skin heals

This hydrating lotion is made with ceramides — fatty acids found in skin cells that make up 50 percent of the outer layer of our skin — which help strengthen the skin’s moisture barrier. This cream also contains amino acids that work to prevent dryness.

Some reviewers say they were hoping for a thicker cream and found this one to be too light and liquidy for their taste.

Best body wash

Price: $

$ Best for: painful skin that needs extra moisture and gentler ingredients than what you would find in traditional soaps or body washes

This body wash contains Avena sativa (oat) kernel flour, which Alexiades says can help soothe sunburnt skin. Its fragrance-free formula makes it a milder cleansing option for sensitive, just-sunburnt skin.

Something to note is that some reviewers say that even though the product is marketed as fragrance-free, it still has a scent. So, it may not be sensitive enough for all skin types and conditions.

Best for pain and inflammation

Price: $$

$$ Best for: super painful and itchy burn areas like the edges of your tan (er, burn) line

This topical anti-inflammatory is dermatologist recommended for reducing pain and itchiness. It contains 1 percent hydrocortisone, which is the maximum strength available without a prescription.

That being said, this topical cream is more for targeted areas than for your whole body. You may also need a lotion that can provide more coverage for the rest of your sunburn.

Price: $

$ Best for: areas where your skin is blistering or your sunburn is particularly severe

Alexiades recommends this product, which provides instant sunburn pain relief. Some studies have also shown that colloidal silver can prevent infection as well.

Silver gel won’t make your sunburn heal faster — it just works for pain and as an anti-inflammatory.

Best for face and lip care

Price: $$

$$ Best for: severely dry and sensitive post-sunburn facial skin

This face cream locks in moisture with aloe vera and squalene, an emollient that King says can help the skin barrier through hydration and by improving the overall texture of the skin. This product is a favorite for post-chemical peel relief, making it a good option for moisturizing the layer of new skin underneath a sunburn.

However, one reviewer says that the lotion is greasy and thick, so it may be better suited for nighttime application only.

Price: $$$

$$$ Best for: restoring an even skin tone and brightening skin as a sunburn heals

King recommends this serum for its potent antioxidant properties, noting that vitamin C can help neutralize free radicals from UV radiation. Reviewers say that a little goes a long way, so you don’t have to use a lot to get the benefits.

But one reviewer says that the serum caused breakouts, while another says that it made her fine lines more pronounced.

Price: $

$ Best for: overly chapped or sunburnt lips

This lip balm doesn’t contain petroleum like many other advanced lip care products, which King says you should avoid post-sunburn. The formulation of aloe, coconut oil, shea butter, and jojoba oil locks in moisture and promotes healing.

Reviews also say that this lip balm has a just-right consistency, and it won’t melt in your pocket on a hot day.

Since this lip balm doesn’t contain SPF, you’ll need to keep your lips in the shade or slather sunscreen on over this product. (But you shouldn’t be out in the sun post-sunburn anyway, right?)

Best all-natural options

Price: $

$ Best for: alleviating redness and that tight post-sunburn sensation while you relax in the tub

King recommends soaking sunburnt skin in milk or plain yogurt to cleanse and moisturize, plus she says that the enzymes in dairy products can provide gentle exfoliation. The proteins, vitamins, and minerals are anti-inflammatory, too, she adds.

This bath soak provides these same effects with just three natural ingredients: goat milk powder, honey powder, and baking soda.

Many reviewers say they thought the price point was too high for the size of the bottle — especially since many people use a sizable amount of product in each bath.

Price: $

$ Best for: hard-to-reach sunburnt areas and for getting full coverage relief with easy application

With vitamin E, lavender, sesame, calendula, and chamomile, this all-natural spray contains soothing ingredients and is easy to apply. Reviewers say it also helps sunburns fade quickly.

This spray won’t stop blistering or peeling, so if you have a severe sunburn, you may need something stronger.

Best for babies and kids

Price: $

$ Best for: kids, babies, and anyone with super sensitive skin

This kids’ cream doesn’t just ease sunburns. It can also soothe diaper rash, bumpy skin, bug bites, and eczema with certified organic aloe vera, jojoba oil, and shea butter.

While the formulation is pretty clean — it’s fragrance-free, dye-free, paraben-free, gluten-free, and doesn’t contain petrolatum or mineral oil — some reviewers took issue with the fact that the product contains alcohol, which may cause irritation.

Best supplements

Price: $

$ Best for: healing a sunburn from the inside out to supplement topical lotions or gels

According to King, research from 2017 shows that high doses of vitamin D — taken 1 hour after sunburn — can significantly reduce redness, swelling, and inflammation. This supplement provides 5,000 international units of vitamin D3 per serving, and reviewers like that the capsule size is small, making the pills easy to swallow.

That being said, certain prescription medication can interfere with the absorption of vitamin D, while others can increase vitamin D levels. Always talk with your doctor before taking any new supplements or vitamins.

Price: $

$ Best for: regaining hydration and staying hydrated while your skin heals

According to Alexiades, oral electrolyte supplementation is key to reversing fluid loss that occurs after a sunburn, and her favorite product for this comes from Pedialyte. Reviewers love these packets because they’re easy to add to glasses of water or a portable bottle for quick hydration.

Not everyone loves the taste of Pedialyte, even when you have a variety pack like this one that lets you sample all the flavors.