Unit 0 & Unit 1 Vocabulary Flashcards

Vocabulary flashcards covering key concepts from Unit 0 and Unit 1: measurement units, temperature scales, density and mass concepts, significant figures, moles and Avogadro's number, isotopes and atomic structure, and periodic table groups.

Nanometer (nm)

A unit of length equal to 10^-9 meters; commonly used to measure atoms and wavelengths.

Micrometer (μm)

A unit of length equal to 10^-6 meters; used for microscopic distances (e.g., cells).

Kilometer (km)

A unit of length equal to 1,000 meters; used for long distances.

Centimeter (cm)

A unit of length equal to 1/100 of a meter; widely used in lab measurements.

Millimeter (mm)

A unit of length equal to 1/1000 of a meter; used for small measurements.

Kelvin (K)

SI unit of temperature; starts at absolute zero and uses the same degree size as Celsius.

Fahrenheit (°F)

Temperature scale primarily used in the US; offsets and scales differ from Celsius.

Density

Mass per unit volume of a substance (e.g., g/cm^3).

Mass

The amount of matter in an object; measured in grams or kilograms.

Volume

The amount of space an object occupies; common units include cm^3 and mL.

Significant figures

Digits that carry meaning contributing to precision in a measurement; reflects uncertainty.

Addition/subtraction sig fig rule

For + and -, the result should have the same number of decimal places as the measurement with the fewest decimal places.

Multiplication/division sig fig rule

For × and ÷, the result should have as many significant figures as the factor with the fewest sig figs.

Grams per cubic centimeter (g/cm^3)

Unit of density in the metric system.

Inches to centimeters conversion

1 inch equals 2.54 centimeters; used for converting measurements between units.

Ounces (oz)

Unit of mass in the avoirdupois system; used in density in some contexts (e.g., oz/in^3).

Microgram (μg)

Unit of mass equal to 10^-6 grams.

Milligram (mg)

Unit of mass equal to 10^-3 grams.

Nanogram (ng)

Unit of mass equal to 10^-9 grams.

Atomic mass unit (amu)

Unit used to express atomic and molecular weights; 1 amu is 1/12 the mass of a carbon-12 atom.

Avogadro's number

6.022 × 10^23 entities per mole; amount of substance containing this many particles.

Mole

Amount of substance containing Avogadro's number of elementary entities.

Isotope

Variants of the same element with the same number of protons but different numbers of neutrons.

Isotope symbol/notation

Notation showing mass number and atomic number or symbol (e.g., A Z X or X with mass number).

Atomic number

Number of protons in the nucleus; defines the element’s identity.

Mass number

Total number of protons and neutrons in the nucleus.

Neutron

Electrically neutral particle in the nucleus with mass about 1 amu.

Proton

Positively charged particle in the nucleus with mass about 1 amu; defines element identity.

Electron

Negatively charged particle surrounding the nucleus; very small mass; balance protons in neutral atoms.

Nucleus

Central region of an atom containing protons and neutrons.

Neutral atom

An atom with equal numbers of protons and electrons; no overall charge.

Alkali metals

Group 1A elements; highly reactive metals (e.g., Li, Na, K).

Alkaline earth metals

Group 2A elements; reactive metals (e.g., Mg, Ca).

Halogens

Group 17 elements; highly reactive nonmetals (e.g., F, Cl).

Noble gases

Group 18 elements; very inert gases (e.g., He, Ne, Ar).

Metalloids

Elements with properties between metals and nonmetals (e.g., Si, Ge).

Transition metals

Elements in the d-block; typical metals with varied oxidation states (e.g., Fe, Cu).

Natural abundance (isotopes)

Proportion of a given isotope found in nature.

Ion

Atom that has gained or lost electrons, acquiring a net electric charge.

Cation

Positively charged ion formed by loss of electrons.

Anion

Negatively charged ion formed by gain of electrons.

Atomic weight vs. atomic mass

Atomic weight is the weighted average of isotopes; atomic mass is the mass of a specific isotope (in amu).