Chemistry Chapter 1: Matter and Properties

Matter and Its Properties

• Matter is composed of tiny particles (atoms) with spaces in between, as described by the Kinetic Particle Theory.
• States of matter include solids (ordered particles, strong attraction), liquids (loosely packed, less attraction, flows), gases (high kinetic energy, weak attraction), and plasma (ionized gas, electrons stripped off).
• Bose-Einstein condensate (BEC) is a state of matter at temperatures near absolute zero where particles behave as a single quantum state.

Properties of Matter

• Physical properties can be observed without changing the substance's composition (e.g., boiling point, density).
• Chemical properties relate to a substance's ability to undergo changes in composition (e.g., combustion of coal).
• Intensive properties do not depend on the amount of substance (e.g., density), while extensive properties do (e.g., mass, volume).

Changes in Matter

• Physical changes do not alter substance composition (e.g., melting, boiling), whereas chemical changes do (e.g., decomposition, rusting).

Classification of Matter

• Mixtures consist of two or more substances that can be separated by physical methods.
• Homogeneous mixtures have uniform composition (solutions), while heterogeneous mixtures do not (e.g., suspensions, colloids).

Methods for Separating Mixtures

• Techniques for separating heterogeneous mixtures include decantation, filtration, flotation, and centrifugation.
• Distillation separates homogeneous mixtures based on boiling points; fractional distillation is for components with close boiling points.
• Crystallization involves forming solid crystals from a solution, and chromatography separates substances based on their movement through a medium.

Elements and Compounds

• Elements are substances that cannot be broken down further and can exist naturally or artificially (118 known elements).
• Compounds form when elements chemically combine and can be broken down into simpler substances only through chemical changes.

Scientific Measurements

• The International System of Units (SI) standardizes measurements globally, with the kilogram as the standard mass unit.
• Weight is defined as the gravitational force on an object and varies with location, while temperature is measured in degrees Celsius, Fahrenheit, and Kelvin.
• Significant figures indicate the precision of measurements, governed by rules about digits and zeros.

Conversion Formulas

• Conversion formulas help switch between temperature scales:
  • Celsius to Kelvin (K = C + 273)
  • Fahrenheit to Celsius (C = (F - 32)/1.80)
  • Kelvin to Celsius (C = K - 273)

Precision, Accuracy, and Measurements

• Precision indicates the closeness of repeated measurements, while accuracy reflects how close a measurement is to the true value.
• Significant figures are crucial for expressing accuracy and precision in measurements.
• Essential rules determine which digits are significant, impacting how scientific data is recorded and interpreted.