The Linda Hall Library STEM Quiz Middle School Edition Question Which of the following diagrams shows what happens during a solar eclipse? 1. (Note: These diagrams are not drawn to scale.)

Question In 2006, Pluto was reclassified as a dwarf planet, meaning there are only 8 planets 2. in our Solar System. Of the planets that remain, which is the smallest?

A. Mars B. Venus C. Uranus D. Mercury

Question 3. The pituitary gland, thyroid, and pancreas are all part of what bodily system? A. Endocrine system B. Nervous system C. Urinary system D. Reproductive system Question Which of the following is released into the atmosphere 4. as a result of photosynthesis?

A. Carbon dioxide B. Water C. Oxygen D. Nitrogen gas

Question Which of these laboratory techniques can separate the components 5. of a mixture based on differences in their boiling points?

A. Filtration B. Distillation C. Chromatography D. Evaporation

Question In the diagram below, which of these phase changes corresponds 6. to the arrow labeled A?

A. Melting B. Deposition C. Sublimation D. Condensation Question Obsidian, , and granite are all examples of what type of rock, often 7. associated with volcanic activity?

A. Sedimentary B. Igneous C. Metamorphic D. None of the above

Question A seismograph is a scientific instrument that would allow scientists 8. to measure the strength of what kind of natural disaster?

A. Measuring the strength of volcanic eruptions B. Measuring the strength of earthquakes and explosions C. Measuring the velocity of flood waters D. Measuring the depth of snow during snowstorms

Question 9. What is the greenhouse effect? A. The process of artificially growing plants indoors B. The result of an accumulation of water vapor and other gases in the atmosphere C. The cause of the extinction of the dinosaurs D. The destruction of the ozone layer Question A cow grazing in a field often disturbs insects that are hiding in the grass. When 10. the insects hop or fly away from the cow, they become more visible to predators. A cattle egret can catch more insects when it looks for food near the grazing cow than when it is further from the cow.

This is an example of what kind of ecological relationship?

A. Parasitic B. Mutualistic C. Commensal D. Predatory

Question This illustration of a heliocentric (sun-centered) solar system comes 11. from a 1543 book written by which Polish astronomer?

A. B. C. D. Question Which of these scientists discovered two new chemical elements 12. in a single year (1898)?

A. Grand Duchess Christina of Lorraine and Ferdinando I de’ Medici B. Irène Joliot-Curie and Frederic Joliot C. Marie and Pierre Curie D. William and Caroline Herschel

Question You are given a solid, silver cube with sides that are 2 cm long. Using a laboratory 13. balance, you determine its mass is 21.6 grams. Based on the table below, the cube is likely made of what metal?

Metal Density Magnesium 1.7 g/cm3 Aluminum 2.7 g/cm3 Tin 7.3 g/cm3 Nickel 8.9 g/cm3 Silver 10.5 g/cm3

A. Magnesium B. Aluminum C. Tin D. Nickel E. Silver Question 14. How many centimeters are in 5 kilometers? A. 500 cm B. 5,000 cm C. 50,000 cm D. 500,000 cm

Question 15. Which of the following sentences describes Isaac Newton's First Law of Motion? A. The force acting on an object is equal to the mass of that object times its acceleration. (F=m*a or F=ma). B. Every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. C. For every action (force) in nature there is an equal and opposite reaction. D. Every object in the universe attracts every other object with a force directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

Question Which of the following is not an example of kinetic energy being turned 16. into potential energy?

A. Pulling back the string on a bow and arrow. B. Running to the top of a steep hill. C. Winding up a toy robot. D. Hitting the gas pedal in a race car. Question Last year, NASA announced the establishment of the Artemis Program, 17. a government-funded effort to transport astronauts to which of the following locations by 2024?

A. Venus B. Europa C. The D. Mars

Question Public health officials often describe efforts to "flatten the curve" during discussions 18. of COVID-19. What does it mean to flatten the curve?

A. Slow the rate of new coronavirus infections B. Make the virus disappear C. Schedule the reopening of businesses and schools D. Schedule the closing of businesses and schools Question Which of these energy sources is responsible for producing the most electrical 19. power in the United States?

A. Coal B. Solar energy C. Natural gas D. Wind

Question The Internet connects computers all over the world. What term might you use to 19. describe a network that is limited to computers in one physical location, such as a home, school, or office building?

A. Local Area Network B. Cloud computing C. Broadband D. The World Wide Web Answers! 1. ANSWER: B

An eclipse occurs when the shadow of a planet or moon falls upon a second body. Eclipses take place when the Sun, Moon, and Earth are perfectly aligned. Since the moon’s orbit is slightly tilted compared to Earth’s orbit around the sun, they are relatively rare astronomical events.

Solar eclipses happen when the moon passes between Earth and the sun, casting a shadow that temporarily blocks out the Sun. In addition, because the Moon’s shadow is much smaller than the Earth, total solar eclipses are only visible within a narrow range on the planet’s surface.

Lunar eclipses occur when Earth passes between the Sun and Moon, as shown in Diagram A. In that case, the Earth casts a shadow across the lunar surface. Unlike solar eclipses, which can only be viewed within a small geographic area, lunar eclipses are visible anywhere on the Earth’s surface where it is nighttime. [KC/6-8.ESS1.A.1]

2. ANSWER: D

Mercury is the smallest planet in the solar system, with a diameter (4,879 km), approximately 38% that of Earth. It is smaller than several natural satellites, including Ganymede and Titan, although it is still larger than Pluto, whose diameter is only 2,302 km.

Mercury is also the innermost planet in the solar system. A fun mnemonic to remember the order of the planets, moving outwards from the sun: My - Mercury Very - Venus Excited - Earth Mother - Mars Just - Jupiter Served - Saturn Us - Uranus Nachos - Neptune

(Before Pluto’s demotion, Mother used to serve us nine pizzas, but now that Pluto has been demoted, we will just have to settle for nachos…) [KC/6-8.ESS1.B.1] 3. ANSWER: A

The organs listed above are part of the endocrine system, which is responsible for synthesizing chemicals called hormones that regulate other bodily functions, including growth, metabolism, and reproduction. The endocrine system consists of 8 major glands:

• The pituitary is considered the “master gland,” which controls many of the other glands’ functions. • The thyroid controls the rate at which cells burn fuels from food to make energy. • The parathyroids control blood calcium levels. • The adrenals control salt and water balance in the body. • The pineal gland produces melatonin, which regulates sleep. • The reproductive glands, ovaries and testes, secrete female and male sex hormones. • The pancreas makes two hormones that control blood sugar levels.

[KC/6-8.LS1.A.3]

4. ANSWER: C

Photosynthesis is the process that allows plants, as well as certain algae and bacteria, to synthesize their own food. The overall reaction can be written out as follows:

6 CO2 + 6 H2O + sunlight C6H12O6 + 6O2

During photosynthesis, plants use energy from the sun to convert carbon dioxide and water into glucose, which can be converted into other energy-storing molecules such as sucrose or starch. Oxygen is released as a byproduct of this process. Indeed, most of the oxygen in Earth’s atmosphere was produced through photosynthesis. [BG/6-8.LS1.C.1] 5. ANSWER: B

There are variety of ways to separate the components of a mixture. Filtration relies on a barrier that is permeable to liquids but blocks the passage of insoluble solids like dirt or sand. For mixtures like salt water, where a solid is dissolved in a liquid, it is often easier to rely on evaporation to remove the solvent and leave the solute behind. Chromatography separates mixtures based on the speed at which each of their components moves through another medium, such as paper or silica gel.

Distillation is a useful technique for separating a mixture of multiple liquids that possess distinct boiling points. The mixture is slowly heated until it reaches the boiling point of one of its components. That substance turns into a vapor, which is then allowed to cool and condense in a separate vessel. By repeating this process as the vessel continues heating, it is possible to isolate each of the mixture’s components. Distillation is one of the oldest known laboratory techniques, and it has a wide range of industrial applications. [BG/6-8.PS1.A.4] 6. ANSWER: C

Arrow A shows solid ice changing directly into water vapor without becoming a liquid. The process of a solid turning into a gas is known as sublimation and explains why ice cubes that have been left in a freezer for a long time begin to shrink inside the tray. One can also observe this phase change when observing dry ice. Dry ice is another name for solidified carbon dioxide. It is sometimes used to keep packages cool because, unlike regular ice, it does not leave any messy liquids behind as it sublimates. Instead, the carbon dioxide turns into a gas and returns to the atmosphere. [BG/6-8.PS1.A.4]

7. ANSWER: B

Geologists classify rocks into three basic types. Sedimentary rocks, like sandstone or shale, form from compressed layers of sediment that accumulate over extended periods of time. Metamorphic rocks, such as marble or slate, are created when other rocks are subjected to high heat and pressure. Igneous rocks, including the three listed in this question, are created when molten rock cools and hardens. Obsidian and basalt are examples of “extrusive” igneous rocks, which form when cools on the Earth’s surface. The presence of either of these rocks indicates the presence of volcanic activity, either now or in the past. Granite, which forms when magma cools underground, is an “intrusive” igneous rock, which can often be found in the interior of mountain ranges. [BG/6-8.ESS2.A.1] 8. ANSWER: A

A seismograph is an instrument that automatically records earthquakes, explosions, or other ground-shaking phenomena. It uses electromagnetic sensors to translate ground motions into electrical changes, which are processed and recorded by analog or digital circuits. Whether it appears on an electronic display or a piece of paper, the resulting reading is known as a seismogram. [KC/6-8.ESS2.A.2]

9. ANSWER: B

The “greenhouse effect” refers to the warming of the Earth’s surface and lower atmosphere caused by the increasing concentration of “greenhouse gases.” The Earth’s surface is naturally warmed by sunlight; infrared (IR) radiation is emitted from Earth’s surface. “Greenhouse gases” in the atmosphere – including carbon dioxide, methane, water vapor, nitrogen oxide, and chlorofluorocarbons – absorb some of the radiation, which increases atmospheric temperature. The warmed atmosphere reflects IR radiation back toward Earth's surface, further raising the surface temperature. [KC/6-8.ESS3.D.1] 10. ANSWER: C

All of these are examples of symbiotic relationships. Symbiosis describes the way two organisms of different species interact based on how the relationship affects one or both organisms.

• In a parasitic relationship, one species gains from the situation, and the other is harmed over an extended period. • In a mutualistic relationship, both organisms benefit equally. • A commensal relationship benefits one side while neither helping nor hurting the other. • Predatory relationships involve one species (the predator) hunting and killing the other (the prey).

The example above represents the commensal type of symbiotic relationship: the bird benefits, but the cow is not affected in a significant way. [KC/6-8.LS2.A.2]

11. ANSWER: A

Nicolaus Copernicus was a religious official who spent his days administering church properties in his diocese in northern Poland. At night, however, he devoted himself to studying the stars. Like most astronomers at the time, he had been taught that the Earth was the center of the universe and that the Sun and other planets traveled around it. By 1510, he had come to believe that this geocentric (Earth-centered) system was flawed and that a heliocentric (sun-centered) model would prove more effective at explaining the motion of the planets.

Copernicus spent the next thirty years of his life gathering evidence for his ideas and writing the manuscript for a book entitled On the Revolutions of the Heavenly Orbs (De Revolutionibus Orbius Coelestium). He was so concerned about critical reaction to his book that he only published it in 1543, when he was on his deathbed. It would be many years before Copernicus’s heliocentric system was accepted by the astronomical community, but his book is a landmark text of the Scientific Revolution—the period between roughly 1500 and 1700 when people started to question ancient authorities and lay the foundations for modern . [BG] 12. ANSWER: C

In July 1898, Marie Skłodowska Curie & Pierre Curie published a scientific paper announcing that they had successfully extracted a new chemical element from a mineral called pitchblende. Since Marie had been born in Poland, the Curies decided to name their discovery “polonium.” On December 26, the Curies announced the discovery of a second element in their pitchblende samples, which they named “radium.” Both substances were radioactive, a term coined by Marie. [KC]

13. ANSWER: B

Density is a measurement of how much matter is contained within a given volume of a substance. It can be calculated by dividing the mass of an object by its volume. (Density= Mass/Volume) Two objects can be the same size but weigh different amounts because each has a different density. The density of a solid or liquid does is not significantly affected by changes in temperature or pressure, which makes it a useful way to identify an unknown substance.

In this case we are being asked to calculate the density of a solid metal cube. The cube’s mass is 21.6 g. The volume of the cube is equal to its length multiplied by its width multiplied by its depth or 2 cm x 2 cm x 2 cm= 8 cm3.

Density is equal to mass divided by volume. In this case Mass/Volume = 21.6 g/8 cm3= 2.7 g/ cm3. Referring to the table above, we can see that this value corresponds to the density of aluminum, so the answer is B. [BG] 14. ANSWER: D

A kilometer is a unit of length equal to 1,000 meters. 5 kilometers would therefore be equal to 5,000 meters. Since each meter consists of 100 centimeters, the final answer is 5,000 m x 100 cm/m, or 500,000 centimeters. [BG]

15. ANSWER: B

Newton’s First Law of Motion states that objects cannot start, stop, or change direction all by themselves. An external force is required to induce such a change. This is sometimes referred to as the “law of inertia.” [KC/6-8.PS2.A.2]

16. ANSWER: D

Kinetic energy is associated with objects in motion. The faster an object is moving, the more kinetic energy it has. Potential energy is the stored energy associated with an object due to its position, shape, or condition. In each of the first three examples, the kinetic energy associated with an object’s motion is being transformed into potential energy. Stretching the bowstring converts the archer’s movements into elastic potential energy, which will turn back into kinetic energy when the arrow is released. The toy robot presents a similar situation; winding it up stores energy in a spring, which causes the robot to move when released. Running to the top of a hill gives an athlete more gravitational potential energy due to their position above the ground. In the case of the race car, hitting the gas causes energy stored in the gasoline to be released, setting the car in motion. This is an example of chemical potential energy being turned into kinetic energy. [BG/6-8.PS3.A.2] 17. ANSWER: C

Neil Armstrong and Edwin “Buzz” Aldrin became the first humans to land on the Moon on July 20, 1969. Over the next three years, ten more astronauts would follow in their footsteps and explore the lunar surface. Since the conclusion of the Apollo 17 mission in December 1972, humans have not returned to the Moon. That may change in a few years thanks to the Artemis Program. The new program is named for Artemis, the Greek goddess of the moon and sister of Apollo. As described on its website, its main goal is “landing American astronauts, including the first woman and the next man, on the moon by 2024.” [BG]

18. ANSWER: A

To "flatten the curve" means to the lower the rate of an infection while extending that rate over a period of time. The slower spread allows for healthcare institutions time to prepare for an influx of infected patients, and not be overwhelmed by a large number arriving at once.

In the diagram above the blue section is the “flattened” part of the curve, indicating a number of infections spread out over weeks or months. The red section shows the same number of cases in a much shorter period. If all the infected need hospitalization at one time it could compromise the level of care provided, as well as possibly infect those working in that hospital. [KC] 19. ANSWER: C

According to the U.S. Energy Information Administration, 38.2% of the electricity produced in the United states in 2019 came from natural gas. Although coal was the leading fuel used in American power plants throughout the 20th century, concerns about pollution and the increasing availability of natural gas have pushed its overall contribution to U.S. power production down to 23.5%. Among renewable energy sources, wind produces the largest share of America’s electricity (7.3%), while solar panels are responsible for only 1.8% of overall power production. [BG]

20. ANSWER: A

When people talk about computer networks, they often refer to the Internet, which allows people to communicate with each other over great distances. During the 1970s, as computers became more common in homes and offices, the value of smaller networks soon became apparent. Engineers at Xerox’s Palo Alto Research Center developed new hardware and software that would allow them to connect their computers to one another. They called this new system, “Ethernet,” and the resulting interconnected computers were known as a “Local Area Network” (LAN). The introduction of wireless networking protocols (Wi-Fi) in the 1990s meant that future LAN setups would not need to rely on physical cables to connect computers to one another. [Further information via Computer History Museum: https://www.computerhistory.org/revolution/networking/19/381] [BG]

Questions written by Kim Carter & Ben Gross