701stilwell - 7th Grade - Science - Benchmark 1

Scientific methods refer to the systematic and organized approach used by scientists to solve problems and answer questions. These methods involve a series of steps, including making observations, formulating hypotheses, conducting experiments, analyzing data, and drawing conclusions. By following these step-by-step procedures, scientists can ensure that their findings are reliable and can be replicated by others in the scientific community.

The statement "The building is red" is a factual statement that describes the color of the building. It is an observation because it is based on direct sensory perception without any inference or interpretation. A conclusion, on the other hand, is a judgment or decision reached after considering evidence or reasoning. In this case, there is no evidence or reasoning involved, just a simple observation of the building's color.

The statement "The liquid smells like peppermint" is an observation because it is a direct sensory perception made by someone. Observations involve gathering information through our senses, such as sight, smell, touch, taste, and hearing. In this case, the person is using their sense of smell to perceive the scent of peppermint in the liquid.

Leaving peeled fruit on a kitchen counter can cause a chemical change resulting in a change in color. When fruits are exposed to oxygen, a process called oxidation occurs, which can lead to a color change. This is commonly observed in fruits like apples or bananas, where the exposed flesh turns brown due to the chemical reactions happening within the fruit. Therefore, the correct sign of chemical change for this example is a change in color.

This statement is an example of a conclusion because it is a logical inference based on observations. The observation is that plants will die if they are watered too little or too much. From this observation, we can conclude that maintaining the right amount of water is crucial for the survival of plants.

Burning wood in a fireplace is an example of a chemical change because it involves the combustion of wood, which is a chemical reaction. During this process, the wood reacts with oxygen in the air to produce carbon dioxide, water vapor, and other byproducts. The release of light and heat is a characteristic sign of this chemical change, as the energy released during the combustion process manifests as a visible flame and heat.

When a chunk of dry ice is at room temperature, it undergoes a process called sublimation, where it changes directly from a solid to a gas. This occurs because the temperature of the room is higher than the sublimation point of dry ice, causing the solid carbon dioxide to vaporize without passing through a liquid phase. As a result, a cloud of carbon dioxide vapor forms.

The measurement of an object's mass is considered a physical property because it is a characteristic of the object that can be measured without changing its chemical composition. Mass is an intrinsic property of matter that remains constant regardless of the object's location or surroundings. It is a fundamental property used to describe the amount of matter in an object and is typically measured using a balance or a scale.

The statement "The water is hot" is an observation because it is a factual statement based on direct sensory experience. It does not involve any inference or reasoning, but rather simply states the current state or condition of the water. A conclusion, on the other hand, would involve drawing an inference or making a judgment based on evidence or reasoning.

The given correct answer is "data". Data refers to the information or facts that are collected or observed. In this case, the temperature of a liquid, the height of a plant, and the observation of one object being smaller than another are all examples of data. These are concrete measurements or observations that can be used as evidence or input for further analysis or decision-making.

A hypothesis is a testable prediction about a possible solution to a problem. It is a proposed explanation or answer to a scientific question, based on prior knowledge and observations. A hypothesis is formulated before conducting an experiment and is used to guide the research process. It is important to note that a hypothesis is not a conclusion, as conclusions are drawn after analyzing the results of an experiment. A hypothesis is also different from a variable, which refers to any factor that can change in an experiment.

The statement "It is going to rain" is a statement of fact that is based on the direct observation of the current weather conditions. It is not a conclusion that is drawn from any reasoning or analysis. Therefore, it can be categorized as an observation rather than a conclusion.

After scientists reach conclusions from the results of their experiments, they communicate their results to other people. This is an important step in the scientific process as it allows for sharing knowledge, validating findings, and promoting further research and discussion within the scientific community. By sharing their results, scientists contribute to the collective understanding and advancement of scientific knowledge.

An explanation of an observation is a process of drawing conclusions or making interpretations based on the available evidence and reasoning. It involves analyzing the data and making logical connections to arrive at a plausible explanation for the observed phenomenon. Inference is the correct answer because it aligns with the definition of drawing conclusions based on evidence and reasoning.

The correct answer is melting ice, mowing the lawn, carving a statue. These examples demonstrate physical changes because they involve a change in the state or appearance of the substances involved, without any new substances being formed. Melting ice changes the state of water from solid to liquid, mowing the lawn changes the height and appearance of the grass, and carving a statue changes the shape and form of the material being carved.

The height of the plant is the dependent variable in this experiment because it is the variable that is being measured and is expected to change as a result of the amount of sunlight. The independent variable would be the amount of sunlight, as it is being manipulated by the researcher to see its effect on the plant's height. The hypothesis is a statement or prediction about the relationship between the independent and dependent variables, and the conclusion is the final result or summary of the experiment.

When a newspaper is left in direct sunlight for a few days and turns yellow, it is evidence of a chemical change. This is because the yellow color indicates a chemical reaction that has occurred within the paper. The sunlight causes the paper's molecules to break down and undergo a chemical reaction, resulting in the change in color. This change is not reversible and indicates a transformation in the chemical composition of the paper, making it a chemical change rather than a physical change.

When an antacid tablet is dissolved in water, it undergoes a chemical change. This is because the tablet reacts with the water to produce a gas, which is carbon dioxide. The formation of a gas is a sign of a chemical change taking place. This can be observed by the bubbling or fizzing that occurs when the tablet is added to water.

The first step in designing an experiment is to state the problem. This involves identifying and clearly defining the question or issue that the experiment aims to address. Without a clear problem statement, it would be difficult to formulate a hypothesis, design a procedure, or analyze the data effectively. Therefore, stating the problem is crucial as it sets the foundation for the entire experimental process.

In an experiment, a factor that does not change is called a constant. This means that throughout the experiment, this particular factor remains the same and does not vary. Constants are important in experiments because they provide a baseline against which the effects of other variables can be compared. By keeping certain factors constant, researchers can isolate the impact of the independent variable on the dependent variable and draw accurate conclusions about cause and effect relationships.

In an experiment, the factors that are measured are known as dependent variables. These variables are influenced by the independent variables, which are manipulated by the researcher. The dependent variables are the outcomes or results that are observed or measured in order to determine the effect of the independent variables. The hypotheses are statements that propose an explanation or prediction about the relationship between the independent and dependent variables. Constants, on the other hand, are factors that are kept the same throughout the experiment to ensure that only the independent variables are affecting the dependent variables.

A judgment based on what has been observed in an experiment is a conclusion. After conducting an experiment and collecting data, scientists analyze the results and draw conclusions based on their observations. These conclusions summarize the findings of the experiment and provide insights into the relationship between variables or the overall outcome of the experiment. Conclusions are important for interpreting and communicating the results of an experiment, and they help to support or refute a hypothesis.

When a solution of sodium nitrate is mixed with a solution of lead nitrate, a chemical reaction occurs. This reaction results in the formation of a precipitate, which is a solid that forms from a liquid solution. A precipitate is a clear indication of a chemical change taking place. The other options, such as a change in color, release of light and heat, and the formation of a gas, may also occur in some chemical reactions, but in this specific example, the formation of a precipitate is the most relevant sign of chemical change.

The ability of an apple to change color when exposed to air is a chemical property. This is because the change in color is a result of a chemical reaction that occurs between the compounds in the apple and the oxygen in the air. It is not a physical property because physical properties are characteristics that can be observed without changing the substance itself, whereas the change in color requires a chemical reaction to take place. It is also not a physical change because physical changes do not alter the chemical composition of a substance, whereas the change in color involves a chemical reaction.

The ability of a pond to freeze over in winter is a physical property because it is a characteristic or behavior of the pond that can be observed and measured without changing the substance itself. It is not a chemical property because it does not involve a change in the chemical composition of the pond. Additionally, it is not a physical or chemical change because the freezing of the pond is a reversible process and does not result in the formation of new substances.

People do experiments to test the effects of independent variables. Independent variables are the factors or conditions that researchers manipulate or control in an experiment to observe their impact on the dependent variable. The dependent variable, on the other hand, is the variable that is being measured or observed to determine the outcome or result of the experiment. By testing the effects of independent variables, researchers can draw conclusions and make inferences about the relationship between these variables and their impact on the dependent variable.