1. Introduction to matter 8th Grade Science
Chapter 2
Introduction to matter
8th Grade Science

2. Properties of Matter
____________is anything that takes up space and has mass.
_____________is the study of the properties of matter and how matter changes
The ____________ and changes in matter depend on its makeup or composition
A __________is a single type of matter that is pure (has a specific set of properties)Examples of pure substances:_________________
Matter
Chemistry
properties
substance
Sugar and salt

3. Properties of Matter Every form of matter has two kinds of properties:
________ properties – characteristics of a pure substance that can be observed without changing it into another substance. A physical property of water is that it freezes at 0
Solid, liquid, gas are physical properties of matter
_________ properties – a characteristic of a pure substance that describes its ability to change into different substances. To observe the chemical properties you must try to change it to another substance. Flammability, reactivity,
Physical
Chemical

4. Examples of physical and chemical properties
Freezing
Bumpy texture and color are physical properties
Flexibility – bend into shapes without breaking
Chemical
Iron forms rust when it is combined with oxygen in air
Silver will react with sulfur in air to form tarnish
Property of gold is that it does not react easily with oxygen and sulfur

5. Elements
An ______________is a pure substance that cannot be broken down into any other substance by chemical or physical means.
Simplest substances
Identified by specific __________and ______________properties
Examples: ______________(foil) and ___________(pennies)
Elements can be in solid, liquid or gas form
Elements are represented by either one or two-letter symbols such as ___(aluminum) or __ (carbon)
element
Physical
Chemical
Aluminum
Copper Al C

6. Particles of Elements
An ____________is the basic particle from which elements are made
Different elements have different properties because their _________ are different.
All matter is made up of _____________
Atoms have the ability to combine with ___________.
When atoms combine they form a ____________- a force of attraction between two atoms.
Atom
atoms
atoms
other atoms
Chemical bond

7. When Atoms Combine…..
Atoms combine to form larger particles called ___________.
Molecules are groups of two or more atoms held together by ________________.
Water – two atoms of _________ chemically bonded to one atom of _________.
Two atoms of the same element can combine to form a _______.
molecules
Chemical bonds
Hydrogen (H)
Oxygen (O)
molecule

8. Compounds All ______is made up of _______
Most _________in nature are found combined with other _________.
A pure substance made up of two or more elements chemically combined in a set ratio is called a ___________
A compound is represented by ____________
The chemical formula show the elements that are found in the compound and the ratio of the ______ Ex. Carbon dioxide- ratio 1:2
matter
elements
elements
elements
compound
Chemical formula
atoms

9. Chemical Formulas
If a different ratio of carbon to oxygen was present – it would be a different___________.
When elements are chemically combined, they form compounds having ________that are different from those of the uncombined elements.
Examples:
silver sulfide
Table sugar
compound
properties

10. Mixtures Elements and compounds are _____________
A __________ is made up of two or more substances – the substances can be elements, compounds, or both.
Mixtures differ from compounds in two ways:
Each substance in a mixture keeps its____________________
Parts of a mixture are not combined in a_________.
Example: soil mixture, sand, clay, water, etc. Not all soil samples are the same
Pure substances
mixture
Individual properties
Set ratio

11. Types of Mixtures
________________ - a mixture where you can see the individual parts. Example: salad
________________ - substances are evenly mixed so that the individual substances cannot be seen. Example: lemonade
______________ is an example of a homogeneous mixture.
Does not have to be a liquid
Air is an example of a solution-gas solution
Brass is an example of a solid solution
heterogeneous
homogeneous
solution

12. Separating Mixtures
A _________ is difficult to separate into its elements
A ________ is not difficult to separate into its components because each component keeps its own _____________.
Methods of separating a mixture:
Magnetic attraction
Filtering the mixture
Distilling a liquid solution
evaporation
Compound
Mixture
properties

13. Measuring Matter
Weight
___________ is a measure of the force of gravity on an object. - on Earth, all objects are attracted towards the center of the earth based on the force of the earth’s gravity. On the moon, you would weigh one sixth of your total weight on earth. ____________ is the measurement of the amount of matter in an object -the mass of your body does not change on the moon * Weight can change with location. Mass does not change with location even when the force of gravity on the object changes.
Mass

14. Units of Mass, Volume, and Density
______________________is the measurement system used by scientists to measure properties of matter.
____________is the amount of space that matter occupies. Formula: length x width x height
____________relates to the mass of a material in a given volume. Formula: mass ÷ volume
International System of Units (SI)
Volume
Density

15. Sinking or Floating
Objects with densities ________than water will sink.
Objects with densities _________than that of water will float.
Density is a ___________property of a substance.
Brainpower – why does the oil in a bottle of salad dressing rise to the top of the bottle?
greater
less
physical

16. Section 2 Assessment Question 1a and 1b Question 2a, 2b, and 2c
Question 4 Calculating Density Practice

17. Changes in Matter
_______________ change is any change that alters the form or appearance of matter but does not make any substance in the matter into a different substance.
Example: sand that is used in an art sculpture is still sand just in a different form
When matter changes state from a solid, liquid, or gas – a _____________change has occurred.
Physical
physical

18. Examples of Physical Changes
_____________
____________
Dissolving
Bending
Crushing
Breaking
Chopping
Filtration
Distillation

19. Chemical Change
_____________ change is a change in matter that produces one or more new substances
- a substance is transformed into a different substance.
- the new substances have ___________ that are different from the original substances
- Examples of chemical changes: burning natural gas, rust, tarnish, and breaking down water into its elements
Chemical
properties

20. Examples of Chemical Change
Description
Example
Combustion
A rapid reaction between fuel and oxygen that results in fire
Gas, oil, or coal burning in a furnace
Electrolysis
Use of electricity to break a compound into its elements or simpler compounds
Breaking down water into oxygen and hydrogen
Oxidation
Slow combination of a substance with oxygen
Rusting of an iron fence
Tarnishing
Slow combination of a bright metal with sulfur or another substance, producing a dark coating on the metal
Tarnishing of brass

21. Law of Conservation of Mass
__________________in the 1770’s made accurate measurements of mass both before and after a chemical change.
His data showed that mass was neither lost nor gained as a result of the change
_____________________ - matter is not created or destroyed
Since mass measures the amount of _________, this law is sometimes referred to as the __________________________
Antoine Lavoisier
Law of Conservation of Mass
matter
Law of Conservation of Matter

22. Conserving Matter

23. Chemical Reaction in Methane
No mass is lost during the combustion of methane gas
During a chemical change, ________ are not lost or gained – they are simply rearranged.
For every molecule of ________ that burns, two molecules of _________ are used.
The ______are rearranged in the reaction, but they do not disappear.
atoms
methane
oxygen
atoms

24. Thermal Energy ____________is the ability to do work or cause change
Chemical or physical changes in _________ includes a change in __________.
______________ is a measure of the average energy or random motion of particles of matter
______________ is the total energy of the particles in an object
__________________is related to the amount of __________________ an object has.
___________________ always flows from warmer matter to cooler matter
matter
Energy
Temperature
Thermal Energy
Temperature
Thermal Energy
Thermal Energy

25. Thermal Energy and Changes in Matter
When matter changes thermal energy is either __________ or ____________
______________ change is a change in which energy is taken in
_______________ change occurs when energy is released or given off
___________ is a chemical change that releases energy in the form of heat and light
absorbed
released
Endothermic
Exothermic
Combustion

26. Forms of Energy Energy comes in many forms: Kinetic Potential Chemical
Electromagnetic
Electrical
Thermal

27. Kinetic Energy Kinetic Energy – the energy of matter in _________.
The smallest particles of matter have __________ energy because they are in constant, random motion.
The kinetic energy of particles contributes to the __________ energy of a substance
A rolling ball has kinetic energy because the particles that make up the ball are in motion.
motion
kinetic
thermal

28. Potential Energy
Potential energy is energy that is ________ as a result of the objects _________.
When a diver climbs to the top of a diving board his/her potential energy ___________.
When you stretch a rubber band, you are giving the rubber band ____________ energy because it has the ability to snap back and do work.
Other types of potential energy: a book on top of your desk – it has the potential to fall off
stored
position
increases
potential

29. Chemical Energy
Chemical energy is the internal energy stored in the _______________ between atoms.
Chemical energy is also a form of _______ energy because the energy is stored.
When a chemical change occurs, the chemical bonds are _______ and new bonds are formed.
Chemical bonds
potential
broken

30. Electromagnetic energy
Electromagnetic energy is a form of energy that travels through _________ as ________.
Examples: radio waves, infrared rays, the waves that heat food in the microwave, ultraviolet waves, and x-rays.
_________ is an example of electromagnetic energy.
__________ changes give off electromagnetic energy such as light from a wood fire.
waves
space
Visible light
Chemical

31. Electrical Energy
Electrical Energy is the energy of ________charged particles moving from one place to another.
___________ move from one atom to another in many ____________ reactions.
_____________ are two metal strips that are used to conduct electrical energy when connected to an electrical energy source such as a ____________.
electrically
electrons
Chemical
Electrodes
battery

32. Transformed Energy
Burning of fuel is a ________ change that transforms ____________ energy and releases it as ____________ energy and ____________ energy.
When you exercise, ___________ energy from food is transformed into __________ energy of your moving muscles.
Photosynthesis – plants transform ____________ energy into _________ energy as they make molecules of sugar.
chemical
Chemical
thermal
electromagnetic
chemical
kinetic
electromagnetic
chemical

33. Section 2-4 Assessment
1a, 1b, 2a, 2b, 2c