Science Class Quiz on Measurements and Matter

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Questions and Answers

What is the purpose of scientific notation?

To simplify the writing of very small or large numbers (correct)

To convert fractions into decimals

To provide precise measurements in chemistry

To represent all numbers in whole number form

What value best represents the temperature indicated on a thermometer if it is estimated to be 4.85°C?

4.9°C

5.0°C

4.85°C (correct)

4.8°C

In scientific notation, what is the coefficient of the number 3.2 x $10^{20}$?

0.32

320

3.2 (correct)

How would you express the diameter of the sun, 1,400,000,000 meters, in scientific notation?

$1.4 x 10^9$ Signup and view all the answers

What is the estimated length of a piece of wood if the possible values given are 4.5 cm, 4.4 cm, and 4.6 cm?

4.55 cm Signup and view all the answers

What are the primary metals that make up bronze?

Copper and tin Signup and view all the answers

Which characteristic defines a heterogeneous mixture?

Components can be easily separated Signup and view all the answers

What is the base unit for measuring mass in the Metric system?

Kilogram (kg) Signup and view all the answers

How are other Metric units related to the base units?

By powers of 10 Signup and view all the answers

Which of the following is an example of how to convert volume in the metric system?

1 kiloliter = 1,000 liters Signup and view all the answers

What defines an exact number in measurements?

Results from counting objects Signup and view all the answers

What does measuring volume involve in terms of dimensions?

Length x Width x Height Signup and view all the answers

What is the relationship between mass and weight?

Weight measures gravitational force on mass Signup and view all the answers

Which of the following correctly defines matter?

Anything that has mass and takes up volume Signup and view all the answers

Which of the following is an example of synthetic matter?

Nylon Signup and view all the answers

What is the primary purpose of the scientific method?

To describe how scientists think and approach problems Signup and view all the answers

Which of the following statements is true regarding chemicals?

Chemicals have the same composition and properties wherever found Signup and view all the answers

Which of the following contains chemicals?

Water Signup and view all the answers

What is the first step in the scientific method?

Make observations and ask questions Signup and view all the answers

Which of these substances is classified as naturally occurring matter?

Planet Earth Signup and view all the answers

What is a chemical in the kitchen that combines various substances?

Toothpaste Signup and view all the answers

Which statement accurately describes the nature of gas?

Gas fills its container and takes its shape. Signup and view all the answers

What is a characteristic of a chemical change?

It converts one substance into another. Signup and view all the answers

Which of the following is an example of a physical property?

Color of a substance. Signup and view all the answers

What defines a pure substance?

It has a constant composition. Signup and view all the answers

Which example illustrates a mixture?

Sugar dissolved in water. Signup and view all the answers

What is a key characteristic of a homogeneous mixture?

It has uniform composition throughout. Signup and view all the answers

Which of these processes is an example of a physical change?

Melting ice. Signup and view all the answers

Which statement is true about an element?

It is a pure substance that cannot be chemically broken down. Signup and view all the answers

What is the mass of 85.32 mL of blood plasma with a density of 1.03 g/mL?

87.9 g Signup and view all the answers

How would you express the density of a substance with a specific gravity of 0.789?

0.789 g/mL Signup and view all the answers

Using the density conversion, how many mL are equivalent to 5.0 g of a substance with a density of 1.05 g/mL?

4.8 mL Signup and view all the answers

What is the relationship between density and specific gravity?

Specific gravity is equal to a substance’s density since the density of water is approximately 1 g/mL. Signup and view all the answers

What is the correct method to cancel units when solving density problems?

Use the inverse density to cancel unwanted units. Signup and view all the answers

What is the scientific notation for the decimal number 0.000138?

1.38 x 10-4 Signup and view all the answers

Which of the following numbers is represented correctly in scientific notation?

0.12 = 1.2 x 10-1 Signup and view all the answers

If a number is expressed as 2.80 x 10–2, what is its value when converted back to standard notation?

0.0280 Signup and view all the answers

Which of the following correctly summarizes how to interpret numbers in scientific notation?

Negative exponents indicate decimal numbers less than one. Signup and view all the answers

How is the number 520000 expressed in scientific notation using three significant figures?

5.20 x 10^5 Signup and view all the answers

Which option correctly describes the process to convert a standard number into scientific notation?

Move the decimal to create a number between 1 and 10; the exponent is positive if moved left. Signup and view all the answers

What is the coefficient in the scientific notation 1.28 x 10^7?

1.28 Signup and view all the answers

Which of these scientific notations represents a number greater than one?

4.9 x 10^1 Signup and view all the answers

Study Notes

Chapter 1: Matter and Measurement

Chemistry is the study of matter—its composition, properties, and transformations.
Matter is anything that has mass and takes up volume.
Naturally occurring matter examples: cotton, silk, hair, sand, gemstones, digoxin (cardiac drug).
Synthetic (human-made) matter examples: nylon, polyester, styrofoam, ibuprofen, many antibiotics.
Antacids, water, glass, and air are all examples of matter.

Atoms and Matter

Chemistry studies the composition, structure, and properties of matter, and the changes it undergoes.
All matter is made up of basic building blocks called atoms.

Chemicals

Chemicals are substances with consistent composition and properties.
Many everyday products contain chemicals. Examples found in toothpaste: calcium carbonate (abrasive), sorbitol (prevents hardening), sodium lauryl sulfate (loosens plaque), titanium dioxide (whitening), triclosan (inhibits bacteria), sodium flourophopshate (strengthens enamel), and methyl salicylate (flavor).
Various examples of chemicals in the kitchen—silicon dioxide (glass), chemically treated water, metal alloys, natural polymers, and natural gas. Various fruits grown with fertilizers and pesticides.

Study Check

Sunlight is not matter, but is energy,
Fruit, milk, and breakfast cereal are matter and contain chemicals.

1.1 Scientific Method

Scientists use a systematic approach called the scientific method.
Steps in the scientific method include observations, hypotheses, experiments, and conclusions.
The scientific method is a set of general principles that helps to describe how a scientist thinks.
Examples of observation: observing new cat, sneezing.
Forming a hypothesis: being allergic to cats.
Testing the hypothesis through experiments: visiting other friends with cats.

Discovery of Penicillin

Penicillin was discovered through scientific observation and experiment.

States of Matter

Matter exists in three states: solid, liquid, and gas.
Solids have a definite volume and shape. Particles are tightly packed in a regular three-dimensional array. Examples: rocks, diamond rings, the iPad.
Liquids have a definite volume, but take the shape of their container. Particles are close together but can move past each other. Examples: water, juice, soda.
Gases have no definite volume or shape. They expand to fill their container. Particles are far apart and move randomly. Examples: air, helium, steam.
Physical change: alters the material without changing the composition. Melting ice, boiling liquid water.
Chemical change: converts one substance into another through a chemical reaction. Examples: burning paper, metabolizing an apple, making water.)

Physical Properties

Physical properties are characteristics that can be observed or measured without changing the substance's composition. Examples: boiling point, melting point, solubility, color, and odor.

Classification of Matter

Pure Substances:
- Elements: substances that cannot be broken down into simpler substances by ordinary chemical means (e.g., aluminum, iron).
- Compounds: substances composed of two or more elements chemically combined (e.g., table salt (NaCl), water (H₂O)).
Mixtures: substances composed of two or more components physically mixed together but not bound chemically.
- Homogeneous Mixtures: have uniform composition throughout (e.g., brass (copper + zinc), sugar dissolved in water).
- Heterogeneous Mixtures: have non-uniform composition throughout (e.g., salad, oil and water).

1.3 Measurements

Measurements involve a number and a unit.
Metric system uses base units—meter (m)—length, gram (g)—mass, liter (L)—volume, second (s)—time.
Prefixes define larger or smaller units. (e.g., kilo-, centi-, milli-).
Significant figures indicate the precision of measurement. Exact numbers are those from definitions or counts (e.g., 10 fingers, 1 meter = 100 cm).

Significant Figures

Significant figures represent the precision of a measurement.
Rules determine which digits are significant:
- All non-zero digits are significant.
- Zeros between non-zero digits are significant.
- Zeros at the end of a number with a decimal point are significant.
- Zeros at the beginning of a number with a decimal point are not significant
- Zeros at the end of a number without a decimal point are not significant.
Rounding rules: Determine which values to keep depends on the next digit.

Scientific Notation

A system for writing very large or very small numbers using powers of 10.
Format: coefficient x 10^exponent; the coefficient is always between 1 and 10 (e.g., .32 x 10^5)

Density (g/cm³)

Density is mass/volume.
Density is calculated from measuring an object's mass and volume.
Less dense materials float on top of more dense materials.

Converting Units (Factor-Label Method)

The factor-label method uses conversion factors to change units from one measurement to another.

Note: The pages from the document are mentioned for ease of reference.

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Test your understanding of scientific notation, measurement units, and the properties of matter with this engaging quiz. Challenge yourself with questions about temperature, mass, volume, and mixtures to reinforce your science knowledge.