Chemistry and Measurements: Study Notes for GOB Chemistry

What is Chemistry?

Definition and Scope

Chemistry is the scientific study of the composition, structure, properties, and reactions of matter. It explores how substances interact, transform, and combine to form new materials.

• Composition: What matter is made of (elements, compounds).

• Structure: How atoms and molecules are arranged.

• Properties: Characteristics such as melting point, density, reactivity.

• Reactions: Processes where substances change into others (e.g., Na(s) + Cl2(g) → NaCl(s)).

Example: The transformation of sodium and chlorine into sodium chloride demonstrates a chemical reaction.

Matter

Definition and Classification

Matter is anything that has mass and takes up space (volume). Matter can be classified based on size:

• Macro: Large, visible objects (e.g., water bottle, human).

• Micro: Small, microscopic objects (e.g., cells, bacteria).

• Particulate: Atomic or molecular level (e.g., atoms, molecules).

Example: A plastic solar cell is matter at the macro scale, while its constituent molecules are at the particulate scale.

Systems for Measuring Matter

English and Metric Systems

Measurement systems provide standardized units for quantifying properties of matter.

• English System: Uses units such as inches (in), feet (ft), yards (yd), miles (mi), quarts (qt), gallons (gal), fluid ounces (fl oz).

• Metric System: Uses base units and prefixes related by factors of 10. For example, meter (m) for length, liter (L) for volume.

Example: 1 mile = 5280 feet (English); 1 kilometer (km) = 1000 meters (Metric).

Measurements: Length (L)

Units and Systems

Length measures the distance between two points.

• English units: inches (in), feet (ft), yard (yd), mile (mi).

• Metric base unit: meter (m).

Note: Measurements of width, height, and distance use these same units. Example: The height of a mountain can be measured in meters (metric) or feet (English).

Metric Conversions for Length

Prefixes and Conversion Factors

Metric prefixes indicate multiples or fractions of the base unit (meter).

Prefix	Symbol	Conversion Factor
Mega	M	1 Megameter (Mm) = 1,000,000 meters (m)
Kilo	k	1 kilometer (km) = 1,000 meters (m)
Base unit	m	1 meter (m)
Centi	c	1 meter (m) = 100 centimeters (cm)
Milli	m	1 meter (m) = 1,000 millimeters (mm)
Micro	μ	1 meter (m) = 1,000,000 micrometers (μm)
Nano	n	1 meter (m) = 1,000,000,000 nanometers (nm)

Example: 1 cm = 0.01 m; 1 km = 1,000 m.

Measurements: Volume (V)

Units and Systems

Volume measures the 3-dimensional space an object occupies.

• Can be derived from length units: $\text{Volume} = \text{length} \times \text{width} \times \text{height}$

• English units: quart (qt), gallon (gal), fluid ounces (fl oz).

• Metric base unit: liter (L).

Example: Volume of a cuboid: $6\,\text{cm} \times 3\,\text{cm} \times 2\,\text{cm} = 36\,\text{cm}^3$

Metric Conversions for Volume

Prefixes and Conversion Factors

Prefix	Symbol	Conversion Factor
Mega	M	1 Megaliter (ML) = 1,000,000 liters (L)
Kilo	k	1 kiloliter (kL) = 1,000 liters (L)
Base unit	L	1 liter (L)
Centi	c	1 liter (L) = 100 centiliters (cL)
Milli	m	1 liter (L) = 1,000 milliliters (mL)
Micro	μ	1 liter (L) = 1,000,000 microliters (μL)
Nano	n	1 liter (L) = 1,000,000,000 nanoliters (nL)

Example: 1 mL = 1 cm3 (cubic centimeter)

Key Points for GOB Chemistry Students

• Be able to identify and classify units of length and volume as metric or English.

• Memorize common metric prefixes and their conversion factors.

• Understand how to convert between units using conversion factors.

• Recognize that metric units are based on powers of ten, making conversions straightforward.

Additional info: These notes are based on the Timberlake textbook, 13th edition, and cover foundational concepts in chemistry and measurement relevant to GOB Chemistry courses.