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Questions and Answers
What is the formula to calculate the density of an object?
What is the unit of measurement for density in standard units?
What is the purpose of the scientific method?
Why does the density of an object not change with the amount of the object present?
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What happens when the density of an object is less than the density of a fluid?
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What is the method used to find the volume of an irregular shaped solid?
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What is a scientific theory?
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What is the force exerted by a fluid on an object that causes it to float or sink?
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What is the role of peer review in the scientific method?
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What is the minimum number of atoms required to form a molecule?
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What is the principle that states the buoyant force of an object is equal to the weight of the fluid displaced?
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What is the difference between accuracy and precision?
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Which of the following is NOT a characteristic of living organisms?
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How is the buoyant force calculated?
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What is the independent variable in an experiment?
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What determines whether an object will sink or float?
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What is the purpose of the experimental design?
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What is the approximate percentage of human body weight comprised of proteins?
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What is the result of biases in an experiment?
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What is the width of a water molecule?
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If the density of an object is greater than the density of the fluid, what will happen to the object?
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What is the acceleration due to gravity on Earth?
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What is the significance of replication in the scientific method?
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Why are nanometers and angstroms not always reliable measurement units?
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What is the sum of each atom within a molecule known as?
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What is the role of background research in the scientific method?
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What is density a measurement of?
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Why do clouds float at different altitudes?
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Which of the following is an example of a very dense material?
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What is generally true about the density of solids, liquids, and gases?
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What is the reason behind the upward buoyant force on an object submerged in a fluid?
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What is the primary factor that determines whether an object will sink or float in a fluid?
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What happens to the fluid pressure as an object is submerged deeper into a fluid?
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What is the term for the ability of an object to float when submerged in a fluid?
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What is the result of an object's density being greater than the density of the fluid it is in?
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What is the purpose of calculating the density of an object?
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What is the unit of measurement for acceleration due to gravity on Earth?
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What is the method used to calculate the volume of a regular shaped solid?
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What is the relationship between the density of an object and its volume?
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What is the term for the force exerted on an object by a fluid?
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What is the primary characteristic of molecules that make up all living and non-living things?
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Why are molecules measured in nanometers and angstroms?
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What is the importance of water in living organisms?
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What is the result of molecules being squeezed into a small space?
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What is the characteristic of solids, liquids, and gases?
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What is the significance of molecular weight in measuring the size of molecules?
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What is the characteristic of lead, gold, brass, and rocks such as granite?
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What is the importance of the four macromolecules in living organisms?
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What is the characteristic of proteins in the human body?
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Why are nanometers and angstroms not always reliable measurement units?
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What is the primary purpose of the scientific method?
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What is the role of the independent variable in an experiment?
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What is the definition of empirical data?
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What is the difference between accuracy and precision?
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What is the purpose of the experimental design?
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What is the result of biases in an experiment?
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What is the role of the dependent variable in an experiment?
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What is the significance of replication in the scientific method?
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What is the definition of a scientific theory?
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Study Notes
Molecules and Living Things
- Molecules are made up of two or more atoms chemically bonded and are the building blocks of living and nonliving things.
- There are different types of molecules, including homonuclear diatomic molecules (e.g., O2) and heteronuclear diatomic molecules (e.g., NaCl).
- Carbon is a common organic molecule found in all living things.
- To be considered a living organism, an entity must meet eight criteria, including growing and developing, evolving, responding to the environment, being made of cells, reproducing, having a genetic code, maintaining homeostasis, and obtaining and using energy.
- The four macromolecules essential for life are proteins, lipids, carbohydrates, and nucleic acids.
- Proteins are the largest macromolecule and make up about 20% of human body weight.
- Water is a common molecule found in all living organisms and is only 0.27 nanometers wide.
Measuring Molecules
- Measuring molecules can be tricky, and there are several different approaches.
- Nanometers and angstroms are metric units used to measure molecules, with one nanometer equal to one-billionth of a meter.
- Molecular weight is a common way to measure the size of molecules, calculated by summing the atomic weights of each atom in the molecule.
Density
- Density is a measurement of how compact something is, with more material or molecules squeezed into a space making it denser.
- Density affects everyday life, including how clouds float at different altitudes, why objects float or sink in water, and how gases move in the atmosphere.
- Examples of dense materials include lead, gold, brass, most metals, and rocks like granite.
- Typically, solids are denser than liquids, and liquids are denser than gases.
- Density can be calculated using the equation density = mass / volume.
Buoyancy
- Buoyancy is the ability of an object to float when submerged in a fluid.
- An object experiences a force from the fluid called fluid pressure, which increases with depth and creates an upward buoyant force.
- Archimedes' Principle states that the buoyant force of an object is equal to the weight of the fluid displaced by the object.
- The buoyant force can be calculated using the variables density, volume, and acceleration due to gravity.
Scientific Method
- The scientific method is a series of steps used by scientists to answer questions about the world.
- The steps include coming up with a question, conducting background research, creating a hypothesis, conducting an experiment, analyzing data, forming a conclusion, and peer review.
- Biases can impact the validity of an experiment if they affect the way a scientist follows the procedure.
- Experiments that follow the scientific method can be replicated and may become a theory if supported enough times.
Experimental Design
- The experimental design is an invaluable process in the scientific community to provide data to support or refute a hypothesis.
- The five steps of the experimental design are defining variables, formulating hypotheses, creating an experimental design process, assigning subjects, and measuring the dependent variable.
Science Experiments
- A science experiment is a way of figuring out the structure and behavior of the world using a systematic method.
- In an experiment, one variable (the independent variable) is changed, and its effect on another variable (the dependent variable) is measured.
- Everything else must be kept the same to ensure a fair test.
- The accuracy of data refers to how close it is to being correct, while the reproducibility (or precision) of data refers to how close together the measurements are.
Molecules and Living Things
- Molecules are made up of two or more atoms chemically bonded and are the building blocks of living and nonliving things.
- There are different types of molecules, including homonuclear diatomic molecules (e.g., O2) and heteronuclear diatomic molecules (e.g., NaCl).
- Carbon is a common organic molecule found in all living things.
- To be considered a living organism, an entity must meet eight criteria, including growing and developing, evolving, responding to the environment, being made of cells, reproducing, having a genetic code, maintaining homeostasis, and obtaining and using energy.
- The four macromolecules essential for life are proteins, lipids, carbohydrates, and nucleic acids.
- Proteins are the largest macromolecule and make up about 20% of human body weight.
- Water is a common molecule found in all living organisms and is only 0.27 nanometers wide.
Measuring Molecules
- Measuring molecules can be tricky, and there are several different approaches.
- Nanometers and angstroms are metric units used to measure molecules, with one nanometer equal to one-billionth of a meter.
- Molecular weight is a common way to measure the size of molecules, calculated by summing the atomic weights of each atom in the molecule.
Density
- Density is a measurement of how compact something is, with more material or molecules squeezed into a space making it denser.
- Density affects everyday life, including how clouds float at different altitudes, why objects float or sink in water, and how gases move in the atmosphere.
- Examples of dense materials include lead, gold, brass, most metals, and rocks like granite.
- Typically, solids are denser than liquids, and liquids are denser than gases.
- Density can be calculated using the equation density = mass / volume.
Buoyancy
- Buoyancy is the ability of an object to float when submerged in a fluid.
- An object experiences a force from the fluid called fluid pressure, which increases with depth and creates an upward buoyant force.
- Archimedes' Principle states that the buoyant force of an object is equal to the weight of the fluid displaced by the object.
- The buoyant force can be calculated using the variables density, volume, and acceleration due to gravity.
Scientific Method
- The scientific method is a series of steps used by scientists to answer questions about the world.
- The steps include coming up with a question, conducting background research, creating a hypothesis, conducting an experiment, analyzing data, forming a conclusion, and peer review.
- Biases can impact the validity of an experiment if they affect the way a scientist follows the procedure.
- Experiments that follow the scientific method can be replicated and may become a theory if supported enough times.
Experimental Design
- The experimental design is an invaluable process in the scientific community to provide data to support or refute a hypothesis.
- The five steps of the experimental design are defining variables, formulating hypotheses, creating an experimental design process, assigning subjects, and measuring the dependent variable.
Science Experiments
- A science experiment is a way of figuring out the structure and behavior of the world using a systematic method.
- In an experiment, one variable (the independent variable) is changed, and its effect on another variable (the dependent variable) is measured.
- Everything else must be kept the same to ensure a fair test.
- The accuracy of data refers to how close it is to being correct, while the reproducibility (or precision) of data refers to how close together the measurements are.
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Description
Learn about the composition of molecules, types of diatomic molecules, and the eight criteria that define a living organism.