Chapter 1 Lecture: Matter and Measurements

Fundamental vocabulary terms and definitions from Chapter 1 regarding matter, classification, chemical reactions, physical units, and energy.

Chemistry

The study of the nature, properties, and transformations of matter.

Matter

The physical material that makes up the universe; anything that has mass and occupies space.

Scientific method

The process of observation, hypothesis, and experimentation used to expand a body of knowledge.

Property

A characteristic useful for identifying a substance or object, such as size, color, temperature, chemical composition, and chemical reactivity.

Physical change

A change that does not affect the chemical makeup of a substance or object.

Chemical change

A change in the chemical makeup of a substance.

Solid

A substance that has a definite shape and volume.

Liquid

A substance that has a definite volume but assumes the shape of its container.

Gas

A substance that has neither a definite volume nor a definite shape.

Pure substance

A substance that has a uniform chemical composition throughout.

Mixture

A blend of two or more substances, each of which retains its chemical identity.

Homogeneous mixture

A uniform mixture that has the same composition throughout.

Heterogeneous mixture

A nonuniform mixture that has regions of different composition.

Element

A fundamental substance that cannot be broken down chemically into any simpler substance.

Chemical compound

A pure substance that can be broken down into simpler substances by chemical reactions.

Chemical formula

A notation for a chemical compound using element symbols and subscripts to show how many atoms of each element are present.

Chemical reaction

A process in which the identity and composition of one or more substances are changed.

Reactant

A starting substance that undergoes change during a chemical reaction.

Product

A substance formed as the result of a chemical reaction.

Physical quantity

A physical property that can be measured, described by both a number and a unit.

Unit

A defined quantity used as a standard of measurement.

SI Unit for Mass

$$\text{Kilogram (kg)}$$

SI Unit for Length

$$\text{Meter (m)}$$

SI Unit for Volume

$$\text{Cubic meter (m}^3\text{)}$$

SI Unit for Temperature

$$\text{Kelvin (K)}$$

SI Unit for Time

$$\text{Second (s)}$$

Scientific notation

A number expressed as the product of a number between $1$ and $10$, times $10$ raised to a power.

Mega- (Prefix)

Symbolized by $M$, it represents the base unit multiplied by $1,000,000$ or $10^6$.

Micro- (Prefix)

Symbolized by $\mu$, it represents the base unit multiplied by $0.000001$ or $10^{-6}$.

Nano- (Prefix)

Symbolized by $n$, it represents the base unit multiplied by $0.000000001$ or $10^{-9}$.

Mass

A measure of the amount of matter in an object.

Weight

A measure of the gravitational force that the earth or other large body exerts on an object.

Significant figures

The number of meaningful digits used to express a value.

Rounding off

A procedure used for deleting nonsignificant figures.

Factor-label method

A problem-solving procedure in which equations are set up so that unwanted units cancel and only the desired units remain.

Conversion factor

An expression of the numerical relationship between two units.

Energy

The capacity to do work or supply heat.

Absolute zero

The coldest possible temperature, assigned a value of $0\,K$, which is equal to $-273.15\,^\circ\text{C}$.

Joule (J)

The SI unit for representing energy.

Calorie (cal)

The amount of heat necessary to raise the temperature of $1\,g$ of water by $1\,^\circ\text{C}$; equivalent to $4.184\,J$.

Specific heat

The amount of heat needed to raise the temperature of $1\,g$ of a substance by $1\,^\circ\text{C}$.

Density

The physical property that relates the mass of an object to its volume; expressed as mass per unit volume.