Science Method and Measurement Quiz
39 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following is a quantitative observation?

  • The sky is blue.
  • The grass is green.
  • Water boils at 100 degrees Celcius. (correct)
  • Water is a liquid.

    • Which of the following is NOT a step in the scientific method?

  • Formulate a hypothesis
  • Conduct a survey (correct)
  • Make observations
  • Develop a theory

    • What is the purpose of a hypothesis?

  • To analyze the results of an experiment
  • To collect data through experimentation
  • To prove a scientific theory
  • To provide a possible explanation for an observation (correct)

    • What is the difference between a qualitative and quantitative observation?

    <p>Quantitative observations use numbers and units, while qualitative observations do not. (A)</p> Signup and view all the answers

    Which of the following statements best describes the nature of the scientific method?

    <p>A flexible process that can be adapted depending on the specific problem. (D)</p> Signup and view all the answers

    Which of the following numbers has three significant figures?

    <p>1.00 * 10^2 (B), 1.008 (D)</p> Signup and view all the answers

    How many significant figures are in the number 0.0405?

    <p>3 (C)</p> Signup and view all the answers

    Which of the following is an example of an exact number?

    <p>The number of students in a classroom (A)</p> Signup and view all the answers

    What is the purpose of significant figures in measured numbers?

    <p>All of the above. (D)</p> Signup and view all the answers

    Why are measured numbers considered inexact?

    <p>Both B and C. (D), Because the person using the measuring device can never be perfectly precise. (A)</p> Signup and view all the answers

    What is the term used for digits that remain the same regardless of who measures them?

    <p>Certain digits (D)</p> Signup and view all the answers

    When reporting a measurement, which digits should be recorded?

    <p>All certain digits plus the first uncertain digit (B)</p> Signup and view all the answers

    What does the uncertainty in a measurement depend on?

    <p>The precision of the measuring device (D)</p> Signup and view all the answers

    In the example of measuring a 25.00 mL water sample, how does it differ from measuring 25 mL?

    <p>25.00 mL indicates a more precise measurement (A)</p> Signup and view all the answers

    What is assumed about the uncertainty in the last number recorded?

    <p>It is ±1 unless indicated otherwise (D)</p> Signup and view all the answers

    How many significant figures are present in the number 0.0030?

    <p>2 (B)</p> Signup and view all the answers

    Which of the following numbers, when expressed in exponential notation, has four significant figures?

    <p>57,600 (B)</p> Signup and view all the answers

    What is the correct representation of 385,500 with three significant figures?

    <p>3.85 × 10^5 (B)</p> Signup and view all the answers

    Identify the number of significant figures in the quantity 0.050080 g.

    <p>5 (B)</p> Signup and view all the answers

    How should the number 0.0000007160 be expressed in exponential notation?

    <p>7.160 × 10–6 (C)</p> Signup and view all the answers

    When converting the mass of caffeine 0.0105 g to significant figures, how many are there?

    <p>3 (A)</p> Signup and view all the answers

    What is the number of significant figures in 5.7600 × 10^4?

    <p>5 (C)</p> Signup and view all the answers

    How many significant figures are there in the number 53,069?

    <p>5 (D)</p> Signup and view all the answers

    Which of the following best defines a mixture?

    <p>Two or more elements or compounds that are physically intermingled (D)</p> Signup and view all the answers

    Which of the following is an example of a chemical change?

    <p>Burning wood (C)</p> Signup and view all the answers

    How can mixtures be separated into pure substances?

    <p>By physical methods (D)</p> Signup and view all the answers

    Which of the following describes a homogeneous mixture?

    <p>It has a uniform composition throughout. (D)</p> Signup and view all the answers

    Which process is an example of a physical change?

    <p>Evaporating water (D)</p> Signup and view all the answers

    Which option is NOT a method of separating components in a mixture?

    <p>Combustion (C)</p> Signup and view all the answers

    What occurs during a chemical change?

    <p>Substances are converted to new substances with different properties. (A)</p> Signup and view all the answers

    Which of the following is an example of a heterogeneous mixture?

    <p>Vegetable soup (C)</p> Signup and view all the answers

    What defines a solid in terms of its properties?

    <p>Has a definite volume and shape (C)</p> Signup and view all the answers

    What is the primary characteristic of a liquid?

    <p>Assumes the shape of its container (D)</p> Signup and view all the answers

    Which statement is true regarding the behavior of gases?

    <p>Gases can be easily compressed (B)</p> Signup and view all the answers

    What is the simplest type of substance that cannot be broken down into simpler substances?

    <p>Element (C)</p> Signup and view all the answers

    Which of the following best describes a compound?

    <p>A substance composed of two or more elements chemically combined (D)</p> Signup and view all the answers

    What is a defining characteristic of a molecule?

    <p>Made up of two or more atoms that are chemically bonded (B)</p> Signup and view all the answers

    How does the density of ethanol compare to that of benzene given their densities of 0.789 g/cm³ and 0.880 g/cm³ respectively?

    <p>Ethanol is less dense than benzene (C)</p> Signup and view all the answers

    Which statement correctly identifies the properties of matter overall?

    <p>All matter has mass and occupies space (C)</p> Signup and view all the answers

    Flashcards

    Chemistry

    The science that studies matter, its properties, and changes, including energy associated with those changes.

    Scientific Method

    A systematic approach involving observations, forming laws and theories, and testing them through experimentation.

    Qualitative Observations

    Observations that do not involve numbers, describing qualities such as color or state.

    Quantitative Observations

    Measurements that involve both a number and a unit, such as temperature or speed.

    Signup and view all the flashcards

    Hypothesis

    A possible explanation for an observation that can be tested through experimentation.

    Signup and view all the flashcards

    Inexact Numbers

    Measured numbers which contain uncertainty due to measurement tools and users.

    Signup and view all the flashcards

    Significant Figures

    Digits in a number that contribute to its precision, including certain and uncertain digits.

    Signup and view all the flashcards

    Leading Zeros

    Zeros that come before all nonzero digits; do not count as significant figures.

    Signup and view all the flashcards

    Captive Zeros

    Zeros between nonzero digits; always count as significant figures.

    Signup and view all the flashcards

    Trailing Zeros

    Zeros at the end of a number; count only if there's a decimal point present.

    Signup and view all the flashcards

    Certain digits

    Numbers that remain consistent regardless of who measures them.

    Signup and view all the flashcards

    Uncertain digits

    Digits in a measurement that must be estimated and can vary.

    Signup and view all the flashcards

    Meniscus

    The curve of liquid in a container, read at the bottom for measurement.

    Signup and view all the flashcards

    Measurement uncertainty

    The degree of doubt in a measurement, based on device precision.

    Signup and view all the flashcards

    Exponential Notation

    A way to express very large or small numbers conveniently using powers of ten.

    Signup and view all the flashcards

    Importance of Zeros

    Not all zeros are significant; only those that enhance accuracy.

    Signup and view all the flashcards

    0.0030 significant figures

    0.0030 has 2 significant figures (the trailing zeros count).

    Signup and view all the flashcards

    Converting to Exponential Notation

    A method to express numbers where leading/trailing zeros can be indicated easily.

    Signup and view all the flashcards

    0.00004715 significant figures

    0.00004715 has 4 significant figures.

    Signup and view all the flashcards

    Mass in Significant Figures

    The mass recorded (e.g., 0.050080 g) follows significant figure rules.

    Signup and view all the flashcards

    Expressing 385,500

    385,500 can be expressed differently based on significant figures: 3.855 × 10^5 (one sf).

    Signup and view all the flashcards

    Matter

    Anything that occupies space and has mass.

    Signup and view all the flashcards

    Solid

    A state of matter with fixed volume and shape; rigid and slightly compressible.

    Signup and view all the flashcards

    Liquid

    A state of matter with a definite volume but no specific shape; takes the shape of its container.

    Signup and view all the flashcards

    Gas

    A state of matter with no fixed volume or shape; highly compressible and fills its container.

    Signup and view all the flashcards

    Element

    The simplest type of substance, made of one type of atom, cannot be broken down further.

    Signup and view all the flashcards

    Molecule

    A structure consisting of two or more chemically bound atoms, behaving as an independent unit.

    Signup and view all the flashcards

    Compound

    A substance composed of two or more elements that are chemically combined.

    Signup and view all the flashcards

    Compressibility

    The ability of a substance to decrease in volume when pressure is applied; varies among solids, liquids, and gases.

    Signup and view all the flashcards

    Mixture

    A combination of two or more substances mixed physically.

    Signup and view all the flashcards

    Homogeneous Mixture

    A mixture with visibly indistinguishable parts; often called a solution.

    Signup and view all the flashcards

    Heterogeneous Mixture

    A mixture with visibly distinguishable parts.

    Signup and view all the flashcards

    Chemical Change

    A change where a substance becomes a new substance with different properties.

    Signup and view all the flashcards

    Physical Change

    A change in form without altering the chemical composition.

    Signup and view all the flashcards

    Separation Methods

    Ways to separate mixtures into pure substances by physical means.

    Signup and view all the flashcards

    Variable Composition

    The proportions of components in a mixture can vary.

    Signup and view all the flashcards

    Chemical vs Physical Change

    Chemical changes create new substances, while physical changes do not.

    Signup and view all the flashcards

    Study Notes

    Chemistry - Chapter 1: Chemical Foundations

    • Chemistry is the science studying matter, its properties, changes, and associated energy.
    • Matter is composed of various types of atoms.
    • Science is a framework for gaining and organizing knowledge, and a procedure for processing and understanding information.
    • The scientific method is a process of studying natural phenomena, involving observations, forming laws and theories, and testing them through experimentation.
    • The scientific method varies based on the problem and the investigator involved

    Steps in the Scientific Method

    • 1. Make Observations:
      • Qualitative observations describe properties without numbers (e.g., sky is blue).
      • Quantitative observations involve both numbers and units (e.g., water boils at 100°C).
    • 2. Formulate a Hypothesis:
      • A proposed explanation for an observation.
    • 3. Perform Experiments:
      • Gather new information to test the hypothesis.
      • Experiments often lead to more observations, restarting the process.

    Scientific Models

    • Theory (model): A set of tested hypotheses explaining a natural phenomenon.
    • Explains why nature behaves in a certain way.
    • Models are constantly refined or replaced as more information becomes available.
      • Explains observed natural behavior in terms of human experiences.
    • Observations: Events witnessed and recorded.
    • Natural Law: A summary of observed (measurable) behavior.
      • Example: Law of Conservation of Mass (mass of materials is unchanged by chemical change.)

    Science Drawbacks

    • Focusing on one theory may limit the ability to see alternatives.
    • Scientists are human and prone to biases.
    • Science is influenced by factors like profit motives, budgets, fads, wars, and beliefs.

    Measurement

    • Measurements contain a number and a unit (e.g., 20 grams).
    • Standard Systems of Units:
      • English system (used in the US)
      • Metric system
      • SI system (International System): Based on the metric system.

    Table 1.1 - Fundamental SI Units

    Physical Quantity Name of Unit Abbreviation
    Mass kilogram kg
    Length meter m
    Time second s
    Temperature kelvin K
    Electric current ampere A
    Amount of substance mole mol
    Luminous intensity candela cd

    Table 1.2 - Prefixes Used in the SI System

    (Includes prefixes, symbols, meanings, and exponential notation)

    Units of Measurement and Prefixes

    • Converting between units using prefixes.

    Measurements of Volume Using a Buret.

    • Reading volume from the bottom of the liquid curve (meniscus).

    Uncertainty in Measurement

    • Measurements always have uncertainty.
    • Uncertainty depends on the precision of the measuring device.
      • Significant Figures: Numbers in which certain digits and the first uncertain digit are recorded.
      • Uncertainty in the last digit is assumed to be ±1 unless indicated otherwise.
    • Types of Errors:
      • Random errors: Measurements can be high or low with equal probability. Occur when determining the value of the last digit of a measurement.
      • Systematic Errors: Occur in the same direction each time (always high or always low).

    Accuracy and Precision

    • Accuracy: Agreement with the true value.
    • Precision: Agreement among multiple measurements of the same quantity.

    Example 1.1 - Uncertainty in Measurement:

    • Analyzing polluted water, a chemist using a pipet to measure a water sample.
    • Using a graduated cylinder to measure a solution's volume.

    Precision and Accuracy Example

    • Graduated cylinder accuracy checked by using a buret to deliver water to 25 mL mark.

    Significant Figures and Calculations

    • Exact Numbers: Have defined values (e.g., 12 in a dozen).
    • Inexact Numbers: Measured values, showing uncertainty through significant figures.

    Rules for Counting Significant Figures

    • Nonzero integers are always significant.
    • Zeros:
      • Leading zeros (before non-zero digits) are insignificant.
      • Captive zeros (between non-zero digits) are significant.
      • Trailing zeros (after non-zero digits) are significant if the number contains a decimal point; otherwise insignificant.
    • Exact numbers generally have infinite significant figures.

    Rules for Significant Figures in Mathematical Operations

    • Multiplication or Division: The result has the same number of significant figures as the measurement with the least number of significant figures.
    • Addition or Subtraction: The result has the same number of decimal places as the measurement with the least number of decimal places.

    Rules for Rounding

    • Round only after the final result to avoid sequential rounding.
    • If the digit to be removed is less than 5, the preceding digit remains the same.
    • If the digit to be removed is 5 or greater, the preceding digit is increased by 1.

    Density

    • Mass per unit volume of a substance.
      • Common units: g/cm³ or g/mL.
      • Density formula: Density = mass/volume

    Classification of Matter

    • Matter: Anything that occupies space and has mass.
      • States of matter: solid, liquid, gas.
      • Properties of Solids: Rigid, fixed volume and shape, slightly compressible.
      • Properties of Liquids: Definite volume, no specific shape, assumes shape of container, slightly compressible.
      • Properties of Gases: No fixed volume or shape, takes the shape and volume of the container, highly compressible, relatively easy to decrease the volume.
    • Mixtures: Have variable composition;
      • Homogeneous (uniform composition).
      • Heterogeneous (non-uniform composition, visibly distinguishable parts).
    • Pure Substances: Have constant composition.
      • Elements: Simplest type of substance, cannot be further broken down by chemical changes, consisting of one type of atom.
      • Compounds: Formed from two or more elements chemically combined, composed of multiple atoms.

    Chemical Change

    • A change that alters the chemical composition of a substance.
    • Forms a new substance with different properties and composition.
    • Example: Burning wood (methane reacting with oxygen to form carbon dioxide and water).

    Physical Change

    • Alters the form of a substance but not its chemical composition.
    • Can be used to separate a mixture into its components.
    • Example: Boiling or freezing water.

    Methods for Separating Mixtures

    • Distillation, Filtration, Chromatography.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Chemistry - Chapter 1 Chemical Foundations PDF

    Description

    Test your understanding of the scientific method and key concepts in measurement, including qualitative vs quantitative observations and significant figures. This quiz covers essential principles that are crucial for accurate scientific inquiry.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser