There are three main phases of matter: solid, liquid, and gas.
Solid: A solid is a phase of matter in which the particles are closely packed together and have a fixed
shape and volume. The particles in a solid are held together by strong intermolecular forces, and they
vibrate in place but do not move around each other.
Liquid: A liquid is a phase of matter in which the particles are close together but can move around each
other. Liquids have a fixed volume, but they do not have a fixed shape and take on the shape of their
container. The particles in a liquid are held together by weaker intermolecular forces than those in a solid.
Gas: A gas is a phase of matter in which the particles are far apart and move around randomly. Gases have
neither a fixed shape nor a fixed volume and will completely fill their container. The particles in a gas are
held together by very weak intermolecular forces.
With the advances in science, we discuss two additional phases of matter that can exist under specific
conditions:
Plasma: A plasma is a highly ionized gas in which the particles are charged and can conduct electricity.
Plasmas are found in stars, lightning, and certain types of light bulbs.
Bose-Einstein condensate: A Bose-Einstein condensate is a state of matter that occurs at extremely low
temperatures when a group of boson particles (particles with integer spin) all occupy the same quantum
state. In this state, the particles behave as a single entity and exhibit wave-like properties.
Solids
Fixed shape
Ice cube, crystals, glasses, plastics
Liquids
Fixed volume-no fixed shape
Water, mercury
Gases
No fixed shape nor volume
Steam; atmosphere
Plasmas
Gas like collection of charged atoms and electrons
The sun and other stars

Phase changes: the processes by which matter undergoes a transition from one phase (i.e., solid, liquid,
or gas) to another. There are six common phase changes that can occur, including:
Melting: The process by which a solid substance transitions into a liquid state, typically as a result of an
increase in temperature.
Freezing: The process by which a liquid substance transitions into a solid state, typically as a result of a
decrease in temperature.
Condensation: The process by which a gas substance transitions into a liquid state, typically as a result of
a decrease in temperature or an increase in pressure.
Vaporization: The process by which a liquid substance transitions into a gas state, typically as a result of
an increase in temperature or a decrease in pressure.
Sublimation: The process by which a solid substance transitions directly into a gas state, without first
becoming a liquid, typically as a result of an increase in temperature or a decrease in pressure.
Deposition: The process by which a gas substance transitions directly into a solid state, without first
becoming a liquid, typically as a result of a decrease in temperature or an increase in pressure.
Latent Heat is the energy that is absorbed or released during the phase change.
Physical and Chemical Properties of Materials are characteristics of matter that help us to distinguish
and identify different substances.
Physical properties are those properties that can be observed or measured without changing the identity
of the substance. Some examples of physical properties include:
Color, Density, Melting and boiling points, Conductivity, Solubility, Hardness, Texture
Chemical properties describe how a substance interacts with other substances and how it changes
chemically. Chemical properties can only be observed when a substance undergoes a chemical change.
Some examples of chemical properties include:
Reactivity, Combustibility, Oxidation potential, Corrosiveness, Toxicity, Stability, Acidity or basicity,
Flammability
It's important to note that physical and chemical properties are related. For example, the melting point and
boiling point of a substance are physical properties, but they can also be affected by the chemical
composition of the substance. Similarly, the reactivity of a substance is a chemical property, but it can
also affect the physical properties of the substance, such as its color or texture.
What about Physical and Chemical Changes? How do we know which one is happening?
A physical change is a change in which the substance remains the same, even though its physical
appearance may change. A chemical change is a change in which a new substance is formed, with new
physical and chemical properties.
Examples:

Melting ice: When ice melts, it undergoes a physical change. The ice changes from a solid to a liquid, but
the water molecules remain the same.
Burning wood: When wood burns, it undergoes a chemical change. The wood reacts with oxygen to form
carbon dioxide, water vapor, and ash. The resulting substances have different chemical properties than the
wood.
Dissolving salt in water: When salt dissolves in water, it undergoes a physical change. The salt crystals
break apart and mix with the water, but the salt molecules remain the same.
Rusting iron: When iron rusts, it undergoes a chemical change. The iron reacts with oxygen and water to
form rust, which has different physical and chemical properties than the iron.
Element or Compound?
Elements and compounds are both types of pure substances, meaning that they are composed of only one
type of matter. However, they differ in their chemical composition.
An element is a pure substance that is made up of only one type of atom. Each element has a unique
atomic number, which corresponds to the number of protons in the nucleus of its atoms. Some examples
of elements include oxygen, carbon, gold, and helium.
A compound is a pure substance that is made up of two or more different elements chemically combined
in fixed proportions. The properties of a compound are different from those of its constituent elements.
Some examples of compounds include water (H2O), carbon dioxide (CO2), and sodium chloride (NaCl).
Elements cannot be broken down into simpler substances by chemical means, whereas compounds
can be broken down into their constituent elements by chemical reactions.
It's important to note that mixtures, in contrast to elements and compounds, are composed of two or more
different types of matter that are physically combined, rather than chemically combined. Mixtures do not
have a fixed chemical composition and their properties can vary depending on the amounts of each
substance present. Some examples of mixtures include air, saltwater, and soil.
Mixtures can be even- homogeneous (think sweet tea), or uneven blends where you see different phases -
heterogeneous (think Oreo Blizzard from DQ!).
Naming chemical compounds follows a set of rules depending on the type of compound being named.
Here are some general guidelines for naming chemical compounds:
Ionic Compounds: Ionic compounds are composed of a metal cation and a non-metal anion. To name an
ionic compound, first write the name of the metal cation, followed by the name of the non-metal anion

with an "-ide" suffix. For example, NaCl is sodium chloride. So we went from sodium and chlorine to
sodium chloride.
Covalent Compounds: Covalent compounds are composed of two or more non-metals. To name a
covalent compound, use prefixes to indicate the number of atoms of each element in the molecule. The
first element in the compound is named using the full element name, while the second element is named
using the root of the element name and an "-ide" suffix. For example, CO2 is carbon dioxide.
Acids: Acids are compounds that produce hydrogen ions (H+) in water. To name an acid, first identify the
anion that is present in the compound. If the anion ends in "-ide", change the suffix to "-ic" and add the
word "acid". If the anion ends in "-ate", change the suffix to "-ic" and add the word "acid". If the anion
ends in "-ite", change the suffix to "-ous" and add the word "acid". For example, HCl is hydrochloric acid.
Organic Compounds: Organic compounds are compounds that contain carbon and hydrogen, often with
other elements such as oxygen, nitrogen, or sulfur. Organic compounds are named based on the number
and type of functional groups present. For example, ethanol is named based on its functional group "-OH"
which is called an alcohol.
Nanotechnology is a field of science and engineering that involves the study and manipulation of
materials at the nanoscale level, typically between 1 and 100 nanometers (nm) in size. This is an
incredibly small scale - for reference, a human hair is about 100,000 nanometers in diameter. Remember
that the prefix “nano” is 10-9.
At the nanoscale, the properties of materials can be different from those at the macroscopic scale. For
example, materials may exhibit different electrical, magnetic, or optical properties due to their small size.
Nanotechnology seeks to understand these unique properties and develop new applications and
technologies based on them.