How are elements arranged?

1. Focus Question: How are the
Elements Arranged?
Elements and Atoms 4-1
Mixtures and Solutions Unit

2. What are these items?
• Describe as completely as possible
what is in the two cups.
• Describe what the two strips are made
of.
• What is this pencil lead made of?
• What about the diamond in my ring?
• My jewelry?

3. Elements and Compounds
• There are two kinds of chemical
substances in the world
– Elements and Compounds
• Elements = one kind of atom only
• Compounds = two or more different
kinds of atoms
• Which substances on the board are
Elements and which are Compounds?

4. Elements and Compounds
• Each substance on our list is different from the
others.
• Formulas for water and carbon dioxide have two
different kinds of atoms. That makes them
compounds.
• What other compounds have we worked with in
science?
• The rest of the substances on our list are elements
• Each of them are made of different elements

5. Three important things to understand
• A sample of an element is made out of one kind
of atom only
• Every element has its own kind of atom. Oxygen
- oxygen atoms, Nitrogen - nitrogen atoms,
Aluminum - aluminum atoms
• Every element’s atom is different than every
other element’s atom.
• There are only 90 different kinds of atoms that
occur naturally on Earth, so there are only 90
different elements on Earth as well.

6. Periodic Table of Elements
• Placement of each element provides
information about its chemical
properties
• Size - elements are ordered from
smallest to largest
• Read across row, then down to next
row
• Two rows dropped below for space

7. Navigating the Periodic Table
• Work in pairs to place the atom disks on
the corresponding elements on the
Periodic Table.
• What do you notice about the
distribution of the atom disks?

8. Elements Checklist
• The 90 elements found on Earth are listed in
alphabetical order.
• Read through the list and check the elements
you know something about or have heard of.
• Write a word on the line after the element to
indicate how that element is used or what
kind of substance it is found in.
• Which ones do we know?

9. Homework
• All matter is made of atoms.
• 90 different atoms on Earth that things
can be made of.
• You, everything you own, everything
you eat is made of elements.
• How many elements can we find in the
things we get at stores?
• Bring in items from the Element Search
list.
• Read Organizing the Elements, pg 42-
47 and answer questions.

10. Vocabulary
• Element - a sample of matter (a substance)
composed of only one kind of atom
• Chemical property of an element - how it
reacts (or doesn’t react) with other elements
• Compound - a combination of two or more
different kinds of atoms that are chemically
combined
• Periodic table - a graphic display of the
elements

11. Content
• What is an element?
• A substance that is made of only one
kind of atom
• What is a compound?
• A substance made up of two or more
different kinds of atoms
• What is the periodic table?
• A graphic display of the elements
• Your questions?