Lecture Notes: Units of Measurement, Temperature, and Energy

These flashcards cover key concepts related to units of measurement, temperature, energy, significant figures, and changes in matter as discussed in the lecture.

Significant Figures

Digits in a number that carry meaningful information about its precision.

Metric System

A decimal-based system of measurement used internationally, consisting of units such as meters, liters, and grams.

Specific Heat

The amount of energy required to raise the temperature of one gram of a substance by one degree Celsius.

Calorie

The energy needed to raise the temperature of one gram of water by one degree Celsius.

Nutritional Calorie

A unit of energy equivalent to 1,000 small calories, often used in food labeling.

Kelvin

The SI unit of temperature; absolute zero is 0 K.

Conversion Factor

A numeric factor used to convert one unit to another.

Heterogeneous Mixture

A mixture where the components can be distinguished and separated physically.

Homogeneous Mixture

A mixture that appears uniform throughout and where the individual components are not distinguishable.

Physical Change

A change that alters the form or appearance of a substance, but does not change its chemical composition.

Chemical Change

A change that results in the formation of new chemical substances.

Periodic Table

A tabular arrangement of elements organized by increasing atomic number, showing periodic properties.

Atom

The smallest unit of an element that retains the properties of that element.

Molecule

A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound.

Kilo-calorie

A unit of energy equal to 1,000 calories; often used in dietary contexts.

BTU

British Thermal Unit; a unit of energy used in heating and air conditioning.

Joule

The SI unit of energy in the International System.

SI Units

The International System of Units used for consistent measurement across science and engineering.