Chemistry: Matter, Density, Separation Techniques

Density

Amount of mass per unit volume, calculated as mass/volume

Accuracy

Closeness of a measured value to an accepted value

Precision

Closeness of a series of measurements to one another

Significant Figures

Digits in a measurement that carry meaning contributing to its precision

Atomic Theory

Concept explaining the nature of matter at the atomic level

Isotopes

Atoms of the same element with different numbers of neutrons

Average Atomic Mass

Weighted average of the masses of all isotopes of an element

Elements

Substances composed of only one type of atom

Compounds

Substances composed of two or more elements in fixed proportions

Mixtures

Physical combinations of two or more substances with variable compositions

Separation Techniques

Methods to isolate components of mixtures based on their properties

Qualitative Data

Descriptive data collected through senses

Quantitative Data

Numerical data collected using instruments with units

Data Analysis

Interpreting and illustrating experiment data to draw conclusions

CER Review

Process of making a claim, providing evidence, and using reasoning in experiments

Error Analysis

Examining discrepancies between measured and actual values

Uncertainty

Measure of doubt in the accuracy of experimental results

Percent Error

Expression of error as a percentage of the accepted value

Properties of Matter

Characteristics that define substances and how they behave

States of Matter

Forms of matter: solid, liquid, gas, based on shape and volume

Atomic Structure

Arrangement of protons, neutrons, and electrons in an atom

Organic Chemistry

Study of carbon-containing compounds like pharmaceuticals

Inorganic Chemistry

Study of matter not containing carbon, like metals and minerals

Physical Chemistry

Focus on behavior and changes of matter and energy

Analytical Chemistry

Study of components and composition of substances

Biochemistry

Study of matter and processes in living organisms

Industrial Chemistry

Chemical processes in industrial settings like paints production

Subatomic Particles

Particles within the atom, e.g., electrons

Plum Pudding Model

Model where electrons are dispersed in a positive cloud

Nuclear Model

Model with a small, dense, positively charged nucleus

Bohr Model

Model where electrons orbit nucleus in fixed shells

Quantum Model

Model based on Quantum Theory, focusing on electron waves

Electron Cloud

Area where an electron is likely to be found

Ions

Charged particles formed by losing or gaining electrons

Mass Spectrometry

Method to measure atomic mass using a mass spectrometer

Atomic Number

Number of protons in an atom

Mass Number

Sum of protons and neutrons in an atom

Rounding

Adjusting a calculated value to match the precision of the original data

Particles

Single atoms or groups of atoms bonded together, functioning as a unit

Element

A pure substance composed of only one type of atom

Compound

A pure substance formed by the combination of two or more different elements

Molecule

The simplest part of a covalent substance retaining all its properties

Chemical Formula

Representation showing the number of each element in a compound

Chemical Bonds

Forces holding atoms together in compounds

Homogeneous Mixture

Uniform mixture with constant composition throughout

Heterogeneous Mixture

Non-uniform mixture where substances remain distinct

Colloid

Mixture with suspended particles larger than in a solution

Suspension

Mixture of immiscible substances that separate over time

Filtration

Separation method using a porous barrier based on particle size

Distillation

Separation technique based on differences in boiling points

Crystallization

Process resulting in the formation of pure solid particles from a solution

Chromatography

Technique separating mixture components based on their ability to travel across surfaces