Worksheets2nd Quarter Periodical Test in General Science 11
Total questions: 48
Worksheet time: 24mins
A chef heats fruit juice for a short time before bottling it to kill germs and prevent spoilage. This food preservation method was named after Louis Pasteur.
Attenuation
Fermentation
Pasteurization
Stereochemistry.
Louis Pasteur found that two substances with the same chemical formula behaved differently because their crystal shapes where mirror images. This idea helped him that microorganisms are also selective. Which later discovery came from this idea?
Fermentation- showing that specific microorganisms cause specific chemical changes.
The swan-neck flask experiment disproving spontaneous generation.
The rabies vaccine made from a weakened microbe.
Antiseptic surgery by Joseph Lister.
In 1878, Louis Pasteur published a statement advocating for hygiene: "If I had the honor of being a surgeon, imbued as I am with the knowledge of the danger of exposure to the germs spread on the surface of all objects, particularly in hospitals, not only would I make use of the ordinary precautions, but I would resort to truly surgical antisepsis..." This statement best supports which conclusion about how Pasteur's research connected chemistry/microbiology to disease prevention?
His work on molecular asymmetry in chemistry directly led to the development of vaccines.
His use of heat (a chemical technique) to kill microbes in wine proved that surgery was dangerous.
He believed that all diseases, including those requiring surgery, were caused by the lack of proper ventilation in hospitals.
His success in proving that microbes cause fermentation (a biological process) was evidence that microbes also cause disease and require proactive chemical/hygiene control.
A homeowner cleans the kitchen and wants to kill germs and whiten stains. They use a product that oxidizes and breaks down organic dirt. Which common household chemical does this job?
It is Sodium Hypochlorite, the powerful disinfecting chemical.
It is the complex component known as the builder, which helps soften water for cleaning purposes.
It is the gentle component known as an abrasive, which safely scours the teeth and removes surface stains.
It is the therapeutic compound known as the leavening agent, which causes dough to steadily increase in volume.
A person uses a foaming cleanser, but their tap water has a lot of minerals (hard water). To make the cleanser work well, it contains a chemical that removes these minerals. What is this ingredient called?
A disinfectant that kills germs.
A builder which softens the water.
A gentle abrasive that scrubs surfaces.
A leavening agent that makes gas when mix with warm liquid.
Baking powder has sodium bicarbonate (a base) and cream of tartar. When mixed with dough, it makes carbon dioxide gas that makes the dough rise. What is the role of cream of tartar in this reaction?
It helps gas escape easily by lowering surface tension.
It softens water to stop hard minerals from reacting.
It disinfects the dough to stop bacteria.
It acts as an acid to activate the base.
A detergent company replaces phosphate in their formula with a biodegradable ingredient to protect the environment. Which government agency in the Philippines is mainly responsible for this regulation?
Food and Drugs Authority (FDA) — checks product labeling.
Department of Trade and Industry (DTI) — checks product quality.
Department of Labor and Employment (DOLE) — ensures worker safety.
Department of Environment and Natural Resources (DENR) — regulates water pollution.
A cleaning spray now has a hazard symbol (like a skull and crossbones) and warning labels because of the Globally Harmonized System (GHS). How do these labels help consumers?
They certify that the factory passed all safety inspections.
They give the product’s exact volume and weight as required by DTI.
They show the product is fully safe and biodegradable, approved by DENR.
They warn about the chemical’s danger so users can handle and store it safely.
Dishwashing soap with non-biodegradable chemicals and preservatives flows into wastewater systems. What long-term effect can this cause on the environment?
It builds up in rivers and seas, harming aquatic life and reducing oxygen in the water.
It releases gases that pollute indoor air and irritate the lungs.
It causes chemical burns when touched without gloves.
It mixes with minerals in hard water and clogs pipes.
When your family bakes pandesal, they use baking soda (NaHCO₃) along with a slightly acidic ingredient like yogurt or buttermilk to help the dough expand and become fluffy in the oven. What specific gas is released during the acid-base reaction of the baking soda that causes the pandesal dough to expand and rise?
Carbon Dioxide
Methane
Oxygen
Sulfur Dioxide
A student is reviewing basic chemistry terminology for a quiz and needs to recall the precise definition of mass as presented in the introductory lesson. What specifically is defined as mass?
The amount of matter.
The volume the space occupies.
The total amount of energy stored in a substance.
A measure of the force of gravity acting on an object.
What was the primary reason Aristotle opposed the idea of atomism proposed by Democritus and Leucippus?
He proposed that water was the ultimate substance of all matter.
He assumed that only observable things could be proven true, rejecting the unseen nature of atoms.
He proved that atoms were not solid and indestructible, which contradicted the atomists' initial claim.
He believed that matter was composed of five elements, not just the two (atoms and void) proposed by Democritus.
A lab technician is asked to classify the physical properties of a newly synthesized compound. They observe that measuring the compound's density yields the same value regardless of the sample size. Based on this observation, how should the technician classify density?
Extensive Property.
Chemical Property.
Reversible Property.
Intensive Property.
A homeowner sees that an iron tool left in the rain has turned reddish-brown- it has rusted. Why is rusting considered a chemical change?
The change can be reverse easily.
It can be observed using our senses.
The substances stay chemically the same.
It forms a new substance with different properties.
In Ernest Rutherford's gold foil experiment, scientists observed that a very small number of alpha particles bounced back directly from the gold foil, as if they had hit a wall. What major characteristic of the atom did this specific observation allow Rutherford to conclude?
The atom is mostly empty space.
Electrons orbit the nucleus in specific, quantized energy levels.
The atom's mass is concentrated in a tiny, highly dense, positively charged nucleus.
The positive charge is uniformly distributed throughout the atom in a "plum pudding" structure
A chemist has two beakers: one with a physical change (like sugar dissolving in water) and one with a chemical reaction (like acid reacting with a carbonate). What is the best sign that a chemical reaction is happening?
Bubbles or gas are produced.
The change can be reversed easily.
The temperature of the substance increases.
A solid (precipitate) or a lasting color change appears.
A chemistry team is assessing the historical value of the alchemists' work. One researcher argues that the alchemists’ pursuit of the Elixir of Life and the belief in turning base metals into gold was entirely detrimental to the development of modern science. Is the researcher's argument an accurate evaluation of the alchemists' contribution, according to the lesson material?
No, because their rigorous experiments led to the discovery of new chemical substances, laying the groundwork for modern chemistry.
Yes, because their goal of seeking immortality was based purely on mysticism and non-scientific beliefs.
No, because they were the first to propose that matter is made of indivisible atoms and empty space.
Yes, because they were unable to create new compounds that are still used in modern labs today.
Dr. Reyes is lecturing to a university class about the fundamentals of energy. She asks a student, Sarah, to define the form of energy that is required to move an object. What is the form of energy that powers any type of matter in motion, as described in Dr. Reyes's lecture material?
Potential Energy
Thermal Energy
Kinetic Energy
Chemical Energy
At a construction site, Mr. David tells an apprentice that a brick wall stores energy because of how it is arranged and where it stands. What kind of energy is this?
Potential energy- energy due to position.
Motion energy- released when the wall falls.
Chemical energy- energy stored in materials.
Mechanical energy- total energy of a system.
Ms. Cruz, a high school chemistry teacher, is explaining that energy must always be involved in a reaction. She asks her students to identify the fundamental reason for this universal involvement. Why is every chemical change accompanied by a release or absorption of energy?
Because new substances must have lower potential energy than the original materials.
Because new bonds formed always release more energy than old bonds absorbed.
Because the reaction system always absorbs heat from its immediate vicinity.
Because bond breaking requires energy, while bond forming emits it.
A research team studies a chemical reaction inside a sealed flask. They call the reaction the system and everything around it the universe. What do we call the area around the system that can exchange energy with it?
The boundary
The system
The surroundings
The Universe
An environmental scientist, Dr. Garcia, is observing a reaction that feels noticeably cool to the touch. She correctly interprets this as heat being drawn from the surrounding air. If a chemical process is described as one that 'absorbs heat from its surroundings,' which term correctly identifies this type of energy transfer?
Decomposition
Endothermic
Exothermic
Synthesis
A biology class is studying Photosynthesis in a Philippine Mango tree. They recognize that this process requires the tree to capture sunlight. Based on the energy requirements, how should the process of photosynthesis be classified?
As an endothermic process, because it absorbs energy (light) from its surroundings.
As an exothermic process because it produces food (chemical energy).
As an isolated system, since it only exchanges light.
As a decomposition reaction.
Bakeshop owner Mr. Lee observes that the chemical reaction between baking soda and an acid in his dough makes the mixture feel cool to the touch. Which term accurately describes the energy flow in Mr. Lee's double replacement reaction?
Endothermic
The system
Isolated
Exothermic
A homeowner, Mrs. Santos, notices the metal railings on her patio are slowly rusting: 4Fe(s) + 3O2(g) → 2Fe2O3(s). What is the best combined classification of this reaction?
Decomposition and Endothermic.
Double Replacement and Endothermic.
Single Replacement and Exothermic.
Synthesis and Exothermic.
The World Health Organization is analyzing the global energy cycle, concluding that all food chains and webs must begin with plants. Which statement best analyzes the two main reasons photosynthesis is considered the "most important biological process"?
It is the only type of reaction that produces an energy-rich product.
It converts CO2 and H2O into simple sugar and stores potential energy.
It uses the green pigment chlorophyll to capture and transform all light energy.
It produces both the organic food molecules and the oxygen needed to support nearly all life on Earth.
A team from the National Geographic reports that without green plants, most other organisms could not survive. Which of the following statements provides the strongest evidence to support the report's conclusion?
Photosynthesis is the process that converts light energy into chemical energy.
The survival of other life forms is dependent on the release of oxygen from plants.
Green plants possess chlorophyll, which can capture, transform, and store energy for all life.
All organisms, except green plants, are dependent on green plants because they cannot directly use solar energy to synthesize food.
Professor Delia at the Philippine Normal University is preparing a lecture slide to summarize the input materials required for photosynthesis. To accurately represent the chemical reaction for photosynthesis, which two input substances must Professor Delia include?
Oxygen (O2) and Glucose (C6H12O6)
Light and Chlorophyll
Carbon dioxide (CO2) and Water (H2O)
Glucose (C6H12O6) and Water (H2O)
A chemist wants to explain what an isolated system is using a real-life example. Which situation best shows an isolated system?
A soda can (exchanges mass before opening, energy always).
An unsealed pot of boiling water (exchanges mass and energy).
A tire pumped full of air with a sealed valve (exchanges energy but not mass).
A sealed, heavily insulated vacuum thermos bottle (exchanges neither mass nor energy).
A chemical supplier labels a substance as an element because it is a pure substance. A student objects, arguing that some pure substances, like water (H2O), are not elements. Based on the classification of matter, how should the student's objection be evaluated?
The objection is incorrect; water is a mixture, not a pure substance.
The objection is incorrect; all pure substances are, by definition, elements.
The objection is correct; water is a heterogeneous mixture that can be easily separated by filtration.
The objection is correct; pure substances are divided into elements and compounds, and water is a compound because it can be broken down into simpler substances.
What is the name of the green pigment in plants that can capture and transform light energy?
Carotene
Chlorophyll
Glucose
Xylem
A scientist analyzes an unknown atom in a mass spectrometer and determines that its nucleus contains 20 protons and 20 neutrons. Furthermore, the surrounding electron cloud contains 18 electrons. Based on these subatomic particle counts, what is the correct mass number and the net charge of this unknown particle?
Mass Number 20, Net Charge 2+
Mass Number 20, Net Charge 1−
Mass Number 40, Net Charge 1−
Mass Number 40, Net Charge 2+
A chef prepares a large batch of vinegar by mixing acetic acid with water. According to the description of solutions, what term best describes the acetic acid, which is the substance being dissolved in the smaller quantity?
Compound
Mixture
Solute
Solvent
An industrial plant produces Bronze, an alloy of copper and tin. When a sample is taken from any part of the cooled metal, the composition is the same. Based on the file's description, why is bronze classified as a Homogeneous Mixture?
It is a solid metal that cannot be separated.
The copper settles out from the tin over time.
It is a solid mixture with a uniform composition throughout.
It is a mixture that can be separated by filtration.
A large tank of industrial Vinegar is tested. Samples taken from the top, middle, and bottom all show the identical concentration of acetic acid. What characteristic of a solution is demonstrated by the identical concentration throughout the tank?
It is classified as a pure substance.
It is uniform in composition throughout.
The particles are large enough to be seen.
The mixture is easy to separate by boiling.
A student shines a laser pointer through four clear liquids: pure water, soda water, salt water, and cornstarch mixed with water. Only the cornstarch mixture shows a visible beam of light passing through it. How does the characteristic of a true solution explain why the salt water and soda water did not show the visible beam?
They are solutions, and their small particles do not scatter light.
They are heterogeneous mixtures that absorb all the light.
Their particles are too large, causing the light to settle.
They are colloids, and colloids scatter light.
A local river is heavily contaminated by runoff. After sitting for an hour, the water sample shows a layer of dirt and clay forming at the bottom of the container. Given that the dirt and clay particles settle out when left undisturbed, how should this untreated river water be classified?
Homogeneous Mixture
True Solution
Heterogeneous Mixture
Pure Substance
A sanitation worker uses Commercial Bleach to disinfect an area. The bleach is a solution of sodium hypochlorite dissolved in water. Which component represents the solvent in this powerful household solution?
The final bleach solution itself.
The corrosive properties of the mixture.
The water that dissolved the sodium hypochlorite.
The sodium hypochlorite, which is the chemical component.
An environmental group is testing how different amounts of salt in water affect plant growth. To make sure the results are valid, what should they include in the experiment?
Put salt directly on the soil.
Measure plant height only once at the end.
Use acid to help the plants absorb the salt faster.
Have a control group that gets only pure water (0% salt).
A student dissolves a pinch of table salt into a large glass of water to make a saltwater solution. In this scenario, what role does the water play, as it is present in the greater quantity?
It acts as the solute.
It acts as the solvent.
It is a chemical reagent.
It is the solid phase of the mixture.
A family stores their strong cleaning chemicals. They have a bottle of Commercial Bleach and a bottle of Vinegar. Applying the best practices for safe chemical storage, what is the most important action regarding these two solutions?
Store them together so they are easy to find.
Pour both down the drain when they are done cleaning.
Keep them unlabeled on the kitchen shelf for convenience.
Store them in separate, secure locations to prevent accidental mixing.
A student observes two liquid samples. Sample A is clear and leaves no residue after filtration. Sample B is cloudy and leaves behind large dirt particles on the filter paper. What is the correct analysis of Sample B compared to Sample A?
Sample B is a solution because it contains water.
Sample A is a pure substance, and Sample B is a compound.
Sample A is a Homogeneous Mixture, and Sample B is a true solution.
Sample B is a Heterogeneous Mixture because its components were easily separated by filtration.
Researchers conducting the plant investigation observe that plants watered with 5% salt solution show severe wilting compared to the 1% group. What analysis can be drawn about the relationship between the solute concentration and the plant's health?
The increase in solute concentration negatively disrupts the plant's absorption process.
Plants are naturally resistant to all saltwater concentrations.
A community is worried that their stream is getting dirty from wastewater with tiny solid particles. What is the best way to stop these solids before they reach the stream?
Heat the water to make it evaporate.
Add a chemical to dissolve all the dirt.
Send the water through a wetland to let the dirt flow out.
Build a system like tanks and filters to separate the solids.
A child is struggling to understand why a salt-water mixture is called a solution when salt and water are obviously two different things. Which simple analogy would be most effective to create a model for the homogeneous nature of the solution?
Throwing rocks into a bucket of sand.
Mixing oil and water that separate into layers.
Two different colored marbles placed side-by-side in a box.
A perfectly blended smoothie where no individual fruit piece can be seen or tasted separately.
A fisherman notices that saltwater from the ocean is creeping into a local freshwater marsh. Evaluating the potential environmental damage, what is the most critical factor regarding the saltwater solution that causes harm to freshwater fish and plants?
The presence of the solvent (water).
The fact that salt is a natural compound.
The solution’s physical inability to scatter light.
The high concentration of dissolved salt (solute), which changes the osmotic balance of the organisms.
A school lab has a container of strong bleach labeled “corrosive and hazardous”. What is the safest way to dispose a small amount of used bleach?
Pour it directly into the sink.
Put the container in the recycling bin.
Keep it stored forever until someone else handles it.
Dilute it with plenty of water and follow local rules for chemical waste disposal.
A clear liquid cannot be separated by filtration and does not scatter light. What does this tell us about the liquid?
It’s river water because it’s only water.
It cannot be a mixture because it is clear.
It’s a heterogeneous mixture with many parts.
It’s a true solution because it’s transparent and its particles are too small to scatter light or be filtered.
