You have 3 free guides left 😟
Unlock your guides
You have 3 free guides left 😟
Unlock your guides

1.2 Phases and Classification of Matter

3 min readjune 24, 2024

comes in three states: , , and . Each state has unique properties based on how its particles behave. Understanding these states helps us grasp how substances change and interact in our world.

Matter can be classified as , , or mixtures. Elements are pure substances, while compounds combine elements. Mixtures blend different substances. Knowing these categories helps us understand the composition of materials around us.

Properties and States of Matter

Characteristics of matter states

Top images from around the web for Characteristics of matter states
Top images from around the web for Characteristics of matter states
  • Solids maintain a fixed shape and volume due to closely packed particles with limited motion (ice, metal, wood)
  • Liquids have a fixed volume but take the shape of the container because particles have more freedom to move than in solids (water, milk, oil)
  • Gases fill the entire container with no fixed shape or volume as particles have high kinetic energy and move randomly (air, helium, carbon dioxide)

Mass vs weight distinctions

  • represents the amount of matter in an object measured in kilograms (kg) or grams (g) and remains constant regardless of location
  • is the force exerted on an object due to gravity measured in newtons (N) and varies depending on the strength of the gravitational field
    • On Earth, weight is often expressed in kilograms-force (kgf) or pounds (lbs)

Conservation of matter applications

  • The states that matter cannot be created or destroyed, only transformed
  • In chemical reactions, the total of reactants equals the total mass of products as atoms are rearranged to form new substances (2H2+O22H2O2H_2 + O_2 \rightarrow 2H_2O)
  • In physical changes, the total mass remains constant as the substance undergoes a change in state or appearance without forming new substances (melting ice, dissolving sugar in water)

Phase transitions and critical points

  • is the temperature at which a changes to a
  • is the temperature at which a liquid changes to a
  • occurs when a solid changes directly to a gas without passing through the liquid phase
  • is the process by which a gas changes to a liquid
  • A visually represents the relationships between temperature, pressure, and physical states of a substance

Classification of Matter

Classification of substance types

  • Elements are substances made up of only one type of that cannot be broken down into simpler substances by chemical means (hydrogen (H), oxygen (O), gold ())
  • Compounds are substances made up of two or more elements chemically combined in a fixed ratio that can be broken down into simpler substances (elements) by chemical means (water (), salt (), glucose ())
  • Mixtures are substances made up of two or more elements or compounds physically combined in variable proportions where components retain their individual properties and can be separated by physical means
    • Homogeneous mixtures (solutions) have a uniform composition throughout (air, salt water, alloys)
    • Heterogeneous mixtures have a non-uniform composition (sand and water, oil and vinegar)

Atoms and molecules in materials

  • Atoms are the smallest unit of an that retains its chemical properties and consist of protons, neutrons, and electrons (carbon atoms in diamond, iron atoms in steel)
  • Molecules are two or more atoms chemically bonded together and can be made up of the same or different elements (oxygen molecules () in air, water molecules (H2O), glucose molecules (C6H12O6) in sugar)
© 2024 Fiveable Inc. All rights reserved.
AP® and SAT® are trademarks registered by the College Board, which is not affiliated with, and does not endorse this website.


© 2024 Fiveable Inc. All rights reserved.
AP® and SAT® are trademarks registered by the College Board, which is not affiliated with, and does not endorse this website.

© 2024 Fiveable Inc. All rights reserved.
AP® and SAT® are trademarks registered by the College Board, which is not affiliated with, and does not endorse this website.
Glossary
Glossary