International STEM Olympiad Grand Final Science Past Papers PDF (Grades 9-10-11)

GRADES 9-10-11 SCIENCE PAST PAPERS  Group Grades 9-10-11 SCIENCE CATEGORY 1....

GRADES 9-10-11 SCIENCE PAST PAPERS  Group Grades 9-10-11 SCIENCE CATEGORY 1. 3. In the experiment shown in the figure, Which of the following statements about there is a bell, a magnet, and a light nuclear fusion is correct? source inside a glass jar. The glass jar is connected to a vacuum tap. What A) It occurs inside stars and inside planets. happens when the vacuum tap is B) It occurs inside the Sun but not in other opened and the air is removed from the stars. glass jar? C) It occurs in planets but not in stars. I. Sound waves cannot travel through an empty space. D) It involves the splitting of atomic nuclei into smaller nuclei. II. The magnetic field created by the magnet cannot propagate in a vacuum. III. Light cannot travel through a 4. vacuum. A) I and II B) II and III C) Only II D) Only I To assess the health of babies in the 2. womb, doctors use a device called a Solar energy, which is essential for life sonogram. Sonograms emit ultrasound on Earth, is generated through nuclear waves that are not audible to the human reactions. These reactions involve the ear. transformation of one atom into another. Which of the following statements about Which of the following statements about ultrasound is correct? solar energy is correct? I. Ultrasound waves have frequencies I. Solar energy is produced through the higher than the upper audible limit of fusion process in the sun's core. human hearing. II. Solar energy is the result of the II. Ultrasound waves have frequencies conversion of helium gas into hydrogen lower than the upper audible limit of human in the sun's core. hearing. III. Solar energy is the outcome of the III. The speed of ultrasound waves in a conversion of hydrogen gas into helium vacuum is faster than the speed of the in the sun's core. sounds we hear. A) I and II B) II and III A) I and II B) II and III C) Only I D) I and III C) Only I D) I and III -1- 01  Group Grades 9-10-11 SCIENCE CATEGORY 5. 6. Graph Play Tone Waves Particles Both Top View Normal Side View Slow In the experiment shown in the figure, there is a fixed sound source and an observer positioned nearby. In the figure, sound waves coming How does the sound appear to the from two sources propagate in the observer when they run towards the same medium. Accordingly, which of stationary sound source with a speed of the following statements about sound V and then move away from it? waves propagating in the same medium is absolutely correct? I. The observer will hear a low-frequency sound when approaching the motionless I. The wavelength of the sounds produced sound source, and a high-frequency sound by the two sources can be different. when moving away. II. The speed of the sounds from the two II. The observer will hear a high-frequency sources can be different. sound when approaching the motionless III. The frequencies of the sounds sound source, and a low-frequency sound produced by the two sources can be when moving away. different. III. The observer will hear sound with longer wavelengths when approaching the A) I and II B) I and III stationary sound source, and sound with C) Only II D) Only I shorter wavelengths when moving away. A) I and III B) II and III C) Only II D) Only I -2- 02  Group Grades 9-10-11 SCIENCE CATEGORY 7. 8. Solar energy, which is essential for supporting life on Earth, is generated Which of the following statements about the through nuclear reactions. These radiation curve shown in the figure is correct? reactions involve the transformation of one atom into another atom. I. The radiation curve for different temperatures peaks at a wavelength that is inversely Which of the following statements about proportional to the temperature. solar energy are correct? II. As the temperature of the blackbody I. Solar energy is produced by the increases, the peak wavelength decreases. fusion process in the core of the sun. III. The intensity at all wavelengths increases as II. Solar energy is the energy released the temperature of the blackbody increases. by the conversion of helium gas into hydrogen in the core of the sun. A) I and II B) I and III III. Solar energy is the energy released C) I, II and III D) Only I by the conversion of hydrogen gas into helium in the core of the sun. A) I and II B) II and III C) Only I D) I and III -3- 03  Group Grades 9-10-11 SCIENCE CATEGORY 9. 10. The figure shows a simulation of In the system shown in the figure, a a photoelectric experiment. In this string is attached to one end of a metal experiment, rays of light from a lamp rod. As a result, we can observe a are directed towards a metal surface. wave that is created by the upward and These rays, also known as photons, downward motion of the metal rod. interact with the metal when they reach If the metal rod moves up and down it. When photons strike the metal, they at a faster rate, which of the following can be absorbed by the metal, causing changes do we observe? electrons to be released or ejected from the metal surface. I. The wavelength of the wave increases. Which color of light will result in the II. The wavelength of the wave remains maximum number of electrons being constant. removed from the metal surface in the photoelectric experiment shown in the III. The frequency of the wave increases. figure? IV. The wavelength of the wave decreases. A) Orange light B) Green light C) Blue light D) Yellow light A) Only II B) II and III C) III and IV D) I and III 11. What is the term used for a powerful explosion that happens when a high- mass star completes its life cycle? A) Supernova B) Black hole C) Nebula D) Solar flare -4- 04  Group Grades 9-10-11 SCIENCE CATEGORY 12. 13. You hear the siren. As the ambulance approaches, the sound gets higher. Once it has passed us, it gets lower. This change in pitch is due to how the sound waves reach our ears and affect our perception. The Universe is filled with entities that we cannot directly see but can Similar to sound, light waves are detect through their impact on visible also influenced by the movement of matter. For example, we can observe the source. When a luminous source the movement of stars and dust is moving, the waves it emits are clouds within a spiral galaxy. However, perceived differently. If the source is something puzzling occurs: the speed approaching us, the waves seem to of stars at the galaxy's edges exceeds have shorter wavelengths and appear what gravity alone would suggest. This.................... fact is undeniable. The visible mass of the galaxy is inadequate to account Conversely, if the source is moving for its dynamics. Such observations away from us, the waves seem to challenge the laws of gravity, unless we have longer wavelengths and appear consider an alternative hypothesis:.................... What is responsible for this Choose the correct colours for the gravitational attraction caused by a dark shorter and longer wavelengths to fill in and invisible substance? the blanks respectively. A) Nights A) Blue-Red B) Dead stars B) Red-Green C) White dwarfs C) Green-Yellow D) Black holes D) Yellow-Blue -5- 05  Group Grades 9-10-11 SCIENCE CATEGORY 14. 16. The concept of "empty" is relative and depends on what we are referring to. For example, we might ask, empty of what? Which one/ones of the following cannot travel through a vacuum? I. Light Which of the following statements best II. Magnetic lines explains the concept of "conservation of mass"? III. Sound I. Determining the mass of an object IV. Heat involves measuring how it responds to gravity. A) Only I II. According to classical physics, B) Only III the mass of a given amount of matter C) I and III remains constant, regardless of its D) I, II and IV state. III. Matter cannot be created or destroyed; it can only undergo changes in its form. 15. IV. The standard kilogram serves as the exclusive reference for all systems of mass measurement. A) I B) II C) III D) IV Which one/ones of the following 17. statements is/are incorrect? Which one of the following is not related to the Schrödinger's cat experiment? I. Kelvin is a unit used to measure the strength of UV lights. II. The Kelvin scale is primarily used in A) B) the scientific world. III. Absolute zero, the null point, is 0 Kelvin, representing the lowest possible temperature. IV. 0 degrees Celsius is a lower C) D) temperature than 0 Kelvin. A) Only II B) II and III C) II and IV D) I and IV -6- 06  Group Grades 9-10-11 SCIENCE CATEGORY 18. 19. Global positioning satellites need to Understanding the composition of consider the fact that two identical a star's atoms is one aspect, but atomic clocks, one on the satellite comprehending how they were created and the other on the ground, tick at and how a star like the sun sustains different rates. This discrepancy is due its brightness over time is a different to the difference in altitude and speed challenge. between the clocks. If we don't account The answer lies within the core of the for this time difference and assume star, where a process called fusion both clocks are synchronized, it can takes place. This fusion involves the lead to a positioning error of up to 11 combination of 4 protons to form a km on Earth's surface. However, by nucleus of ________ (2 protons + 2 correcting this temporal drift, the GPS neutrons), which then releases energy. system achieves an accuracy of less than a metre. Fill in the blank with the correct element to explain the fusion reactions To determine its position, a GPS occurring at the core of the Sun: receiver relies on data received from atomic clocks aboard satellites. By A) Hydrogen B) Helium knowing the positions of the satellites in orbit and calculating the time it takes C) Carbon D) Oxygen for signals to reach the receiver, it can deduce the distance between them. To 20. solve a mathematical equation with four unknowns (the receiver's 3D position and the clock divergence), signals from at least four satellites are needed. Which of the following theories is utilised for GPS? A) Einstein's theories of relativity. B) Newton's first, second, and third laws of Which of the options completes the motion. famous quote by Albert Einstein? C) Galileo's theory of motion. 'Two things are infinite: the universe D) Kepler's Laws of Planetary Motion. and..................... and I'm not sure about the universe.' A) Energy B) Human Stupidity C) Time D) Science -7- 07  Group Grades 9-10-11 SCIENCE CATEGORY 21. 22. White phosphorus, red phosphorus, NH3(aq) + H2O(l) ™ NH4OH(aq) ™ and black phosphorus share similar types of atoms and chemical properties, NH41+(aq) + OH1–(aq) despite having different physical When ammonia dissolves in water, it properties. forms a basic solution. A small quantity Which of the following options stands of the dissolved ammonia reacts with out from the others when considering water to produce ammonium hydroxide, carbon in the same context? which then dissociates into ammonium and hydroxide ions. A) Diamond B) Coal Accordingly, which of the following C) Graphite D) Fullerenes statements about the reaction described above is not correct? A) The reaction is reversible. B) If NaOH and NH4Cl are mixed, some ammonia would be produced. C) Ammonia is a weak base. D) The double arrows indicate that ammonia is very slightly soluble in water. 23. 8 OOxygen 15.999 What is the correct order, from greatest to smallest, for the amount of oxygen? I. An atom of oxygen II. A molecule of oxygen III. A gram of oxygen A) III > II > I B) II > III > I C) I > II > III D) III > I > II -8- 08  Group Grades 9-10-11 SCIENCE CATEGORY 24. 26. Which one of the following properties of gold makes it useful for jewellery? I. Malleable Which of the following statements are II. Inert correct about compounds? III.Colour I. Compounds are made of at least two kinds of atoms. IV. Purity II. There is a fixed ratio between the A) I B) I-III C) II-IV D) I-II-III elements forming a compound. III. Compounds can be formed by electron transfer. A) I B) II C) I and II D) I-II and III 25. 6 C Carbon 12.011 Consider the carbon atom, its components, and how they interact. What are the subatomic particles that make up a carbon atom? I. Molecules II. Electrons III. Neutrons IV. Protons A) Only I B) II and III C) I, II and III D) II, III and IV -9- 09  Group Grades 9-10-11 SCIENCE CATEGORY 27. 28. Which one of the following elements Matter often exhibits a high level of is used in telephone wires and radio order, with a precise arrangement receivers because of its magnetic and structured pattern. Scientists property? began exploring well-ordered matter in the late 18th century, and in the 20th A) Fe (Iron) century, Von Laue and the Braggs made significant progress by using X-rays to B) Co (Cobalt) study matter. Their findings revealed C) Cu (Copper) the well-ordered structure through D) Ag (Silver) diffraction patterns. In a crystal, there is a perfect and well- ordered arrangement of molecules that extends throughout the entire body. Each molecule is surrounded by a set of other molecules in a definite symmetrical way. Which of the following substances are examples of crystalline solids? I. Table salt II. Quartz III. Diamond IV. Sugar A) I and IV B) II and III C) I, II and III D) I, II, III and IV -10- 10  Group Grades 9-10-11 SCIENCE CATEGORY 29. 31. Consider two samples of water weighing 10 g and 100 g. Which of the following statements is/are correct? I. The boiling points of the two samples Which organelle is responsible for the are the same. production of ATP, the energy currency of the cell? II. The densities of the two samples are the same. A) Nucleus III. The types of molecular forces B) Mitochondria present in the two samples are different. C) Golgi apparatus A) I B) I and II C) II D) I and III D) Endoplasmic reticulum 30. substance formula atomic weight carbon C 12.011 g/mol water H2O 18.015 g/mol. table salt NaCl 58.443 g/mol. gold Au 196.967 g/mol. Atomic weights of carbon (C), water (H2O), table salt (NaCl) and gold (Au) are given in the table above. Accordingly, which of the following substances contains the greatest number of molecules in its structure? A) 12 g of Carbon B) 36 g of Water C) 58.5 g of Table salt D) 127 g of Gold -11- 11  Group Grades 9-10-11 SCIENCE CATEGORY 32. 34. Which of the following is a characteristic of prokaryotic cells? Which of the following is an example of a biotic factor in an ecosystem? A) Presence of a nucleus B) Membrane-bound organelles A) Temperature C) Single-celled organisms B) Soil pH D) Larger in size than eukaryotic cells C) Sunlight intensity D) Predators 33. What is the process by which plants convert sunlight into chemical energy? A) Photosynthesis B) Respiration C) Transpiration D) Germination -12- 12  Group Grades 9-10-11 SCIENCE CATEGORY 35. 37. Which of the following is a major technological challenge faced by autonomous cars? Which of the following is an example of a vestigial structure in humans? A) Limited availability of advanced sensors and cameras A) Eyebrows B) Inability to adapt to changing weather B) Fingernails conditions C) Wisdom teeth C) High energy consumption leading to D) Lungs reduced efficiency D) Lack of compatibility with existing road infrastructure 36. Which of the following is the primary factor that limits the range of electric cars? A) Battery efficiency B) Charging speed C) Tire wear D) Motor power -13- 13  Group Grades 9-10-11 SCIENCE CATEGORY 38. 40. Which of the following questions is Which of the following is not among the outside the scope of information an causes of the greenhouse effect? artificial intelligence bot would provide? A) Deforestation A) What is the capital of France? B) Burning fossil fuels B) How many countries are there in the C) Volcanic eruptions world? D) Industrial processes C) Can you tell me how to hack into someone's computer? D) Who directed the movie “Titanic”? 39. Which of the following would not help reduce air pollution? A) Using public transportation B) Carpooling (sharing a car for transportation) C) Planting more trees D) Burning fossil fuels -14- 14