IONA Catholic SS G.12 Earth and Space Science Past Paper - Oct 2, 2024 PDF

## IONA Catholic SS ## G.12 Earth and Space Science ### Unit 1 - Astronomy **Name: Kamila Djemileva** **Wednesday Oct 2, 2024** **Total Marks** * Part A: Multiple Choice (Knowledge and Understanding) 3/20 marks * Part B: Short Answer (Thinking) 18.3/20 marks * Part C: Application 8/8 marks **...

## IONA Catholic SS ## G.12 Earth and Space Science ### Unit 1 - Astronomy **Name: Kamila Djemileva** **Wednesday Oct 2, 2024** **Total Marks** * Part A: Multiple Choice (Knowledge and Understanding) 3/20 marks * Part B: Short Answer (Thinking) 18.3/20 marks * Part C: Application 8/8 marks **88%** ### Part A: Multiple Choice Circle the letter of the choice that best completes the statement or answers the question. 1. Which branch of astronomy involves the behaviour and physical properties of celestial objects using mathematical models? * a. astrophysics * b. cosmology * c. cosmetology * d. stellar astronomy 2. One astronomical unit is equal to: * a. the distance light travels in 1 year * b. the distance between the Earth and the Sun * c. the distance between Earth and Venus * d. the distance light travels in our solar system 3. Which of the following is **NOT** a way to measure distances in space? * a. Stellar Parallax * b. Spectroscopy (measures composition, speed) * c. Absolute Magnitude * d. Cepheid Variables 4. The following are comparisons between emission and reflection nebulae: * i) Both are formed by clouds of dust and gas, but emission nebulae are clouds of ionized gas * ii) Emission nebulae emit light while reflection nebulae reflect light * iii) Emission nebulae are a form of bright nebulae while reflection nebulae are not Which of the above comparisons are true? * a. ii only * b. i and ii only * c. ii and iii only * d. all three are true 5. A star that has a blue-shifted spectrum is most likely moving: * a. toward the earth. * b. away from the sun. * c. around the Milky Way Galaxy. * d. toward a black hole. 6. A star that experiences regular changes in brightness over time is called a: * a. Cepheid variable. * b. supernova. * c. binary star. * d. quasar. 7. A cloud of gas and dust that is dense enough to block light is known as: * a. a planetary nebula * b. an emission nebulae * c. a reflection nebulae * d. a dark nebula 8. The most numerous type of galaxy in our local group is: * a. elliptical galaxy * b. irregular galaxy * c. spiral galaxy * d. smooth galaxy 9. The difference between dark matter and dark energy is: * a. dark matter has been found but dark energy has not * b. dark matter causes the universe to accelerate outward and dark energy allows stars to orbit quickly around galaxies * c. dark matter allows stars to orbit quickly around galaxies and dark energy causes the universe to accelerate outward * d. there is no difference as both are terms to describe the same phenomena 10. Which law is useful for estimating the surface temperature of a star once the peak wavelength of the spectrum has been found? * a. Hubble's Law * b. Newton's Law of Universal gravitation * c. Stefan-Boltzmann Law * d. Wien's Law 11. The Wein's Displacement law states that: * a. the wavelength at which the maximum amount of radiation occurs is a constant equal to 2900 times the product of its inverse temperature. * b. The total intensity of the EMR radiated is proportional to the fourth power of its temperature. * c. the force of attraction between two objects is directly proportional to the product of the masses and inversely proportional to the square of its distance. * d. galaxies are receding from us at speeds that are proportional to their distances. 12. The black lines across the spectrum of the sun or a star are caused by: * a. dark nebula * b. absorption of light by atoms in the star * c. emission of light by atoms in the star * d. planets getting in the way 13. Which stage of the Big Bang did galaxies form? * a. the very early universe * b. the early universe * c. during structure formation * d. atoms have always existed 14. The universe is said to be open if: * I - gravity is strong enough to stop the expansion in a finite time * II - the density of the universe is less than the critical density * a. I only * b. II only * c. I and II * d. neither I or II 15. The final stage for a star which is as massive as the sun is: * a. a black hole * b. red giant * c. white dwarf * d. neutron star 16. M class stars are the coolest in temperature, this means that their colour is: * a. blue * b. white * c. yellow * d. red 17. A main sequence star is stable because: * a. the outward pressure from heat is balanced by the inward pressure from gravity * b. the inward pressure from heat is balanced by the outward pressure from gravity * c. the inward pressure from both heat and gravity are balanced * d. the outward pressure from both heat and gravity are balanced ### Part B: Short Answer (Thinking) 1. The universe is thought to be 13.8 billion years old. How old is the universe in terms of the lifetime of a star of the Sun's mass? [2 T] 2. At the time of its development, there were two theories explaining the beginning of the universe. State and describe these two theories and explain why one prevailed over the other. [4] 3. Scientists have not been able to find dark matter or dark energy even though they believe most of the universe is made of these two substances. Distinguish between the two and explain why scientists believe they exist even though we haven't found them. [4 T] 4. a) Define the apparent and absolute magnitude of a star. [2 T] b) The table below shows the absolute magnitude and apparent magnitude of the stars Sirius and Polaris. | Star | Absolute Magnitude | Apparent Magnitude | |---|---|---| | Sirius | -1.42 | -1.46 | | Polaris | -3.63 | 1.97 | By considering the data for each star individually, deduce, without numerical calculation but giving your reasoning, which star is the furthest from the Earth. [3 T] 5. The figure below shows part of the spectrum of light received from a star as well as the spectra of light from several elements. The spectra consist of dark lines running from top to bottom over a bright horizontal continuous spectrum. * a) State what type of spectra these are known as. Explain your answer. [2 T] * b) Using the spectra of the sample elements, determine the elemental composition of the mystery star. [1 T] ### Part C: Application 1. Astronomers have noted that all galaxies have shown red-shifts and that the amount of these shifts increase the farther away the galaxies are. What would it mean if astronomers suddenly started to note that all of these galaxies now started to show blue shifts? What would this mean to the fate of our universe? [4 A] 2. Scientists realized that there needed to be imperfections in the matter at the start of the big bang in order for galaxies to form. Using your understanding of stellar birth and gravity, explain why scientists spent so much time looking for these imperfections as proof of the big bang. [4 A]