Chapter 2.1 NotesSeptember 8, 2014
• Grab a textbook and return quietly to your seat
• Write your EQ at the top of page 26 in your journal “What is the relationship between elements and compounds?”
When you enter…..• Grab a textbook and return quietly to your seat
• Write your EQ at the top of page 26 in your journal “What is the relationship between elements and compounds?”
Vocabulary Use KIM Notes to define the following
words:1. Substance2. Molecule3. Compound4. Chemical Formula5. Ratio
Matter Matter is anything that has mass and
takes up space A substance is a single kind of matter
that is pure meaning that it always has a specific makeup and set of properties
Examples- sugar, table salt Non-examples- butter, milk
Physical Properties Properties of a pure substance that can
be observed without changing it into another substance
Examples: Hardness, Texture, Color, State of Matter, Flexibility, Conductivity
Diamonds are the hardestnatural material
Flexibility
Chemical Properties A characteristic of a pure substance that
describes its ability to change into a different substance
Properties include flammability and reactivity
Question: What must you do to observe a
chemical change?
Think….Pair…..Share Helium does not react with any other
substance. Is it accurate to say that helium has no chemical properties?
Elements Are the simplest substances All matter in the universe is made up of
slightly more than 100 elements An element cannot be broken down into
any other substance by chemical or physical means
An atom is the basic particle from which all elements are made
When atoms combine Atoms combine with a chemical bond to
form larger particles called molecules- two or more atoms held together by a chemical bond
https://www.youtube.com/watch?v=IOXxFaHbIXg
Compounds Most elements are found in nature combined
with other elements. A compound is a pure substance made of two or
more elements chemically combined in a set ratio
(Read Math Skills Box p.40) Represented by a chemical formula which shows
the elements and the ratio of atoms Compounds have different properties from those
that are uncombined elements (Ex: Na is very reactive, table salt-NaCl- is not)
Mixtures Most materials are not pure substances
(elements or compounds) A mixture is made of two or more
elements or compounds that are not chemically combined or combined in a set ratio
Each substance in a mixture keeps its individual properties
Types of Mixtures
Heterogeneous You can see the
different parts
Homogeneous So evenly mixed
that you can’t see the different parts
Example: Solution
Question… Why is it correct to say that sea water is
a mixture?
Scientific Scramble
Video https://www.youtube.com/watch?v=
AfXxZwNLvPA