1. Introduction to Matter
Physical Science
Chapter 2

2. Matter Matter is anything that has mass and takes up space.
All of the universe is made up of matter.
Characteristics of matter are called properties.
Some special physical properties of matter included: color, odor, size, shape, texture and hardness.

3. Physical Properties
The general physical properties of matter are mass, weight, density and volume.
A physical property is a characteristic of a substance that can be observed without changing the identity of the substance.

4. Chemical Properties
Chemical properties describe how a substance changes into other new substances.
Chemical properties include:
Flammability
Reaction with oxygen
Electonegativity
Reactivity

5. Classes of Matter Matter can be found in four categories:
Mixtures: Glass of Lemonade with Ice
Solutions: Lemonade
Elements: H, or Hydrogen
Compounds:H20, or Water

6. Elements
A pure substance is a type of matter in which the following are true:
all the particles are alike
the same through out and does not separate
always has the same physical properties
An element is the simplest type of pure substance.

7. Elements and Atoms
An atom is the basic particle from which all elements are made and the smallest part of an element that has all of the same properties.
Chemical symbols are a way of representing elements using letters.
Each symbol consists of one, two or three letters, for example, C for carbon.

8. Compounds
Compounds are pure substances that are made up of two or more elements chemically combined in a set ratio.
Compounds can only be separated into the individual elements through chemical reactions.
Compounds are represented by chemical formulas.

9. Chemical Formulas
Chemical formulas are combinations of chemical symbols that represent the elements that make up a compound.
Chemical formulas tell us which elements are present and how many atoms of each element.
Subscripts are used to tell how many atoms of each element are present.
Subscripts are placed on the lower right of the chemical symbol.

10. Mixtures
A mixture is made up of two or more substances that are together, but not chemically combined.

11. Properties of Mixtures
The following three things are true about the substances in a mixture:
not chemically combined, so the substances keep their own identities and properties
can be present in any amount, they are not combined in a set ratio
can also be separated by simple physical means such as filtration, evaporation, distillation or magnetism

12. Types of Mixtures
Mixtures are classified according to how well they are mixed.
There are two major classes of mixtures:
Heterogeneous mixtures
A mixture that does not appear the same throughout Ex. Salad
Homogenous mixtures
A mixture that appears to be the same throughout Ex. Glass of Lemonade

13. Measuring Matter
Matter is measured in terms of its general physical properties including:
Weight
Mass
Volume
Density
In science, the International System of Units (SI) or metric system is used to measure all properties of matter.

14. Mass & Weight Mass is the amount of matter in an object.
The mass of an object is constant, it does not change with location.
Mass only changes when matter is added or removed.
The standard unit of matter is the kilogram (kg), but grams (g) and milligrams (mg) can also be used for smaller amounts.

15. Weight Another general property of matter is weight.
Weight is the pull of gravity on an object’s mass.
Because gravity changes with location, weight is a changeable property.

16. Gravity Gravity is the force of attraction between two objects.
All objects exert a gravitational pull on other objects.
The gravity is dependent upon the size of the objects and the distance between them.
The larger the objects the greater the gravity.
The larger the distance between the objects, the less the pull of gravity.

17. Weight & Gravity
The pull of gravity on an object determines its weight.
Therefore, as the pull of gravity decreases, so does an object’s weight.
The formula for weight is
Mass x Gravity = Weight
The metric unit of weight is the newton, N.

18. Volume & Density Volume is the space an object takes up.
The metric units of volume are the liter (L), milliliter (mL), and the cubic centimeter (cm3.)
Density is defined as the mass per unit volume of an object.
The formula for density is
Density = Mass / Volume

19. Density All matter has density.
Density can be used to identify the type of matter you are working with.
The density of water is 1.0 g/mL.
Finding the density of an object and determining if it is greater or smaller than water will tell you if the object will float.

20. Changes in Matter Matter can change in two different ways:
Physical Change: any change that alters the form or appearance but does not change the substance into a different substance
Chemical Change: A change in matter that produces one or more new substances with different properties than the original substance

21. Physical Changes in Matter
Physical changes are divided into:
Changes of state such as: changing a solid to a liquid or a liquid to a gas
Changes in appearance include: dissolving, crushing, breaking or filtering a substance.

22. Chemical Changes
Chemical changes are also called chemical reactions and must follow the law of conservation of mass.
The law of conservation of mass states that matter can neither be created nor destroyed by a chemical reaction.
Examples of chemical changes include:
Combustion
Electrolysis
Oxidation
Tarnishing

23. Matter & Thermal Energy
In both physical and chemical changes a change in thermal energy occurs.
Ex.. Burning a candle or bending a paper clip
Thermal energy is the total energy contained in all the particles of an object.
Temperature is a measurement of the thermal energy of an object or substance.

24. Changes in Thermal Energy
Two kinds of changes in thermal energy can occur:
Endothermic: a change in which energy is absorbed by the substance
Ex. Melting ice
Exothermic: a change in which energy is released by the substance
Burning a marshmallow

25. Forms of Energy Energy can occur in several different forms.
The forms of energy are:
Kinetic
Potential
Chemical
Electromagnetic
Electrical
Thermal

26. Kinetic & Potential
Kinetic energy is the energy of motion, such as an airplane flying.
All moving objects have kinetic energy, even the smallest atoms are vibrating in place and therefore have kinetic energy.
Potential energy is stored energy or the energy an object has due to position or shape.
An example of potential energy is a stretched rubber band.

27. Chemical Energy
Chemical energy is a form of potential energy that is stored in the bonds between atoms.
Chemical energy is released when a reaction occurs, breaking the bonds and releasing the energy in the form of thermal, electromagnetic, or electrical energy.

28. Electromagnetic Energy
Electromagnetic energy is energy in the form of electromagnetic waves.
Examples of electromagnetic energy include:
Radio waves
Light waves
UV waves
X-Rays

29. Electrical Energy
Electrical energy is the transfer of electrical charges from one place to another.
Electrical energy is carried by moving electrons and is more commonly called electricity.
Any type of energy can be transformed into another type of energy through different physical and chemical changes of matter.