Chemistry semester 1 final

Chemistry

Study of matter and its interactions.

Qualitative Data

Descriptive information without numerical values.

Quantitative Data

Numerical information representing measurements.

SI Units

Standard units for scientific measurements.

Length

Distance measured in meters (m).

Mass

Amount of matter measured in kilograms (kg).

Time

Duration measured in seconds (s).

Volume

Space occupied, measured in liters (L).

Temperature

Degree of heat measured in Kelvin (K).

Metric Prefixes

Prefixes like kilo- and milli- for unit conversions.

Density

Mass per unit volume, expressed as g/cm³.

Accuracy

Closeness of a measurement to the true value.

Precision

Reproducibility of measurements under unchanged conditions.

Percent Error

(|Measured - True| / True) x 100.

Significant Figures

Digits that carry meaning contributing to precision.

Pure Substance

Material with a uniform and definite composition.

Mixture

Combination of two or more substances.

Homogeneous Mixture

Uniform composition throughout, like saltwater.

Heterogeneous Mixture

Non-uniform composition, like salad.

Atom

Basic unit of matter, smallest particle.

Molecule

Two or more atoms bonded together.

Atomic Number

Number of protons in an atom's nucleus.

Mass Number

Total number of protons and neutrons.

Isotope

Atoms with the same number of protons, different neutrons.

Alpha Radiation

Helium nuclei emitted during radioactive decay.

Beta Radiation

Electrons emitted from a decaying nucleus.

Gamma Radiation

High-energy electromagnetic radiation emitted during decay.

Nuclear Fission

Splitting of a heavy nucleus into lighter nuclei.

Nuclear Fusion

Combining light nuclei to form a heavier nucleus.

Half-life

Time required for half of a radioactive sample to decay.

Nuclear Reaction

Process where nuclei change, releasing energy.

Chain Reaction

Self-sustaining series of nuclear fissions.