CBSE Class 10th science term 1 board exam: Important 20 assertion reason questions and answers for tomorrow’s exam
Tomorrow is the CBSE Science exam and to make it easier for you all who studies at the last moment, we’ve compiled 20 important assertion reason based questions that can help you top your exam.
Preparing for exams from the beginning of the session is not what students really do and they only study when the tensions of board exams hit them. Then you all know, instead of studying the chapters thoroughly, students look for important questions and answers so that they can prepare themselves with the best.
Not to worry, we are your saviours for tomorrow’s exam. As you all know CBSE is conducting class 10th board exams term 1. The board examination conducted the first exam for class 10th i.e. Social Science yesterday.
Tomorrow is the Science exam and to make it easier for you all who studies at the last moment, we’ve compiled 20 important assertion reason based questions from chapter 1 that can help you top your exam.
Chapter 1 – Chemical Reactions And Equations
In the following questions, a statement of assertion (A) is followed by a statement of the reason (R). Mark the correct choice as:
a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Assertion (A): Decomposition of vegetable matter into compost is an example of exothermic reactions.
Reason (R): Exothermic reactions are those reactions in which heat is evolved.
2. Assertion (A): When HCl is added to zinc granules, a chemical reaction occurs.
Reason (R): The evolution of a gas and change in colour indicate that the chemical reaction is taking place.
3. Assertion (A): Calcium carbonate when heated gives calcium oxide and water.
Reason (R): On heating calcium carbonate, a decomposition reaction takes place.
4. Assertion (A): Brown fumes are produced when lead nitrate is heated.
Reason (R): Nitrogen dioxide gas is produced as a by-product due to the decomposition of lead nitrate.
5. Assertion (A): White silver chloride turns grey in sunlight.
Reason (R): Decomposition of silver chloride in presence of sunlight takes place to form silver metal and chlorine gas.
6. Assertion (A): Pungent smelling gas is produced when sulphur burns in the air.
Reason (R): Sulphur trioxide is formed on reaction of sulphur with oxygen.
7. Assertion (A): In a reaction of copper with oxygen, copper serves as a reducing agent.
Reason (R): The substance which gains oxygen in a chemical reaction acts as a reducing agent.
8. Assertion (A): In the electrolysis of water, the volume of hydrogen liberated is twice the volume of oxygen ……formed.
Reason (R): Water (H,0) has hydrogen and oxygen in the ratio of 1:2 by volume.
9. Assertion (A): Corrosion of iron is commonly known as rusting.
Reason (R): Corrosion of iron occurs in presence of water and air.
10. Assertion (A): The balancing of chemical equations is based on the law of conservation of mass.
Reason (R): Total mass of reactants is equal to the total mass of products.
11. Assertion (A): In a balanced chemical equation, the total mass of the reactants is equal to the total mass of the products.
Reason (R): Mass can neither be created nor destroyed during a chemical change.
12. Assertion (A): Iron articles are painted so as to prevent them from rusting.
Reason (R): When the surface of iron is coated with paint, its surface does not come in contact with oxygen and moisture therefore rusting does not take place.
13. Assertion (A): Chemical reaction changes the physical and chemical state of a substance.
Reason (R): When an electric current is passed through water (liquid), it decomposes to produce hydrogen and
oxygen gases.
14. Assertion (A): When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide.
Reason (R): The decomposition reaction takes place on the application of heat, therefore, it is an endothermic reaction.
15. Assertion (A): Zinc reacts with sulphuric acid to form zinc sulphate and hydrogen gas and it is a displacement reaction.
Reason (R): Zinc reacts with oxygen to form zinc oxide.
16. Assertion (A): Chips manufacturers usually Ilush bags of chips with a gas such as nitrogen to prevent the chips from getting oxidised.
Reason (R): This increases the taste of the chips and helps in their digestion.
17. Assertion (A): Exposure of silver chloride to sunlight for a long duration turns grey due to the formation of silver by decomposition of silver chloride.
Reason (R): In this process, sublimation of silver chloride takes place.
18. Assertion (A): Rusting of iron metal is the most common form of corrosion.
Reason (R): The effect of rusting of iron can be reversed if they are left open in sunlight.
19. Assertion (A): AgBr is used on photographic and X-ray film.
Reason (R): AgBr is photosensitive and changes to Ag and bromine in presence of sunlight and undergoes decomposition reaction.
20. Assertion (A): Magnesium ribbon keeps on burning in an atmosphere of nitrogen.
Reason (R): Magnesium reacts with nitrogen to form magnesium nitride and this reaction is a combination reaction.
Kerala LSS USS result 2026: Official website slow? Check how to download scorecard online
The Kerala CM Kids LSS USS result 2026 has been declared online. Here is a comprehensive troubleshooting guide and step-by-step process to download your scorecard if the official portal bpekerala.in is down or unresponsive.
The Kerala Public Examination Section has officially announced the Kerala CM Kids LSS and USS result 2026. The scorecard link is live for candidates who sat for the scholarship eligibility examinations conducted in February 2026.
However, shortly after the declaration, several students and parents encountered difficulties trying to log onto the main portal, bpekerala.in. Due to a massive surge in simultaneous traffic from eager candidates, the official website has experienced temporary server slowdowns, loading delays, and intermittent error screens. Media reports indicate that the portal might stay slow during peak hours, but authorities ensure that the result data is perfectly safe and live online.
Technical glitches right after a major result declaration are quite common due to infrastructural limitations during peak traffic. Some of the primary factors contributing to the current loading errors include:
High visitor traffic: Thousands of students trying to load the homepage simultaneously.
Server overload: Simultaneous database requests leading to temporary unresponsive servers.
Mobile compatibility limitations: Heavy traffic coupled with certain mobile browsers causing slow rendering times.
Step-by-step guide to download Kerala LSS USS result 2026
If you are experiencing slow loading speeds on the primary web server, you can carefully try the following steps to download your marksheet:
Step 1: Navigate to the official website at bpekerala.in and let the landing page load completely without interrupting.
Step 2: Find and click on the link labeled “CM Kids LSS USS Result 2026” or head directly to the dedicated “Results” tab on the interface.
Step 3: Enter your accurate credentials, which include your Registration Number and Date of Birth (formatted as DD/MM/YYYY), precisely as mentioned in your original hall ticket.
Step 4: Click on the “Submit” or “View Result” button. If the screen takes time to process, avoid refreshing multiple times as it can block your session.
Step 5: Once your breakdown of scores appears on the dashboard, download the digital copy or capture a screenshot, then print a physical copy for any future administrative or school needs.
Alternative links and troubleshooting tips
If bpekerala.in fails to open entirely, candidates are advised not to panic. A backup official digital platform has been set up to ease the main server load. Students can log into pareekshabhavan.kerala.gov.in to access mirrored links for checking their LSS and USS scholarship scores.
Additionally, you can follow these easy technical fixes to bypass server bottlenecks:
Clear browser data: Empty your browser cache or open the link using an Incognito/Private window.
Change connectivity: Switch your internet connection from mobile data to a stable Wi-Fi connection, or vice versa, to reset data routing.
Switch your browser: Try alternative web browsers like Mozilla Firefox or Google Chrome instead of default system web viewers.
Check during off-peak windows: Wait for about 15 to 30 minutes and re-attempt during non-peak windows when server traffic naturally drops down.
CBSE makes three languages mandatory for Classes 9 and 10 from July 1
CBSE has announced that students in Classes 9 and 10 must study three languages from July 1, 2026, though no board examination will be conducted for the third language during the initial rollout.
The Central Board of Secondary Education has announced that students in Classes 9 and 10 will be required to study three languages from July 1, 2026, as part of the implementation of the National Education Policy (NEP) 2020 and the National Curriculum Framework for School Education (NCFSE) 2023.
Under the revised structure, students will study languages under the R1, R2 and R3 format. The board has clarified that two of the three languages must be Indian languages.
However, CBSE has stated that there will be no Class 10 board examination for the third language, also referred to as R3, during the initial phase of implementation.
What the new language structure means
According to the updated curriculum framework, students will choose three different languages. The same language cannot be selected at more than one level simultaneously.
The board has explained the structure as:
R1: Any language offered by CBSE
R2: A language different from R1
R3: A third language different from both R1 and R2
The move is aimed at promoting multilingual education in line with NEP 2020 recommendations.
No board exam for third language initially
CBSE has clarified that although the third language will become mandatory for Classes 9 and 10, students will not immediately face a board examination for R3 in Class 10.
Reports said the full implementation of the three-language board examination structure is expected to happen gradually over the coming years.
Schools asked to prepare for rollout
The board has already directed schools to finalise language options and upload details on the OASIS portal to ensure smooth implementation of the revised policy.
CBSE has also indicated that temporary textbook arrangements and interim measures for language teacher shortages may be introduced during the transition phase.
The National Testing Agency (NTA) has announced that the NEET UG 2026 re-examination will be conducted on June 21 following the cancellation of the earlier exam amid allegations of a paper leak.
The original NEET UG 2026 examination, held on May 3, was scrapped after investigative agencies flagged concerns regarding the integrity of the exam process. The matter is currently under investigation by the Central Bureau of Investigation (CBI).
NTA issues fresh schedule
According to the official announcement, candidates who had registered for the cancelled examination will not be required to submit fresh applications for the re-test. Existing registrations will remain valid for the June 21 examination.
The agency has also advised students and parents to rely only on official NTA communication channels for updates related to admit cards, examination centres and other examination-related notifications.
Paper leak investigation underway
The NEET UG paper leak case has triggered a nationwide probe, with the CBI making multiple arrests in connection with the alleged leak network. Investigators are examining how question papers were allegedly circulated before the examination.
Reports have suggested that handwritten copies of the question paper were allegedly scanned and circulated through messaging networks and intermediaries ahead of the examination.
Students await admit cards and city slips
The NTA is expected to release fresh city intimation slips and admit cards ahead of the June 21 examination date. Candidates have been advised to regularly check the official NEET website for updates regarding examination centres and instructions.
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