b1: classifying matter. b1-1: what are elements?
TRANSCRIPT
I. BUILDING BLOCKS OF MATTER
Matter is everything that takes up space and has matter.
Matter can be found in: The food we eat The water we drink The air we breathe
Matter may feel different, have different smells, or may appear differently
As a matter of fact, there are over 100 substances in our world!
I. BUILDING BLOCKS OF MATTER
Elements Substances that cannot be broken down into other
substances by heat, light, or electricity. Examples: Iron, Gold, Oxygen
Why are they “Building Blocks”? Each element is like a letter of the alphabet. Different combinations make-up different substances
found in our world.
I. BUILDING BLOCKS OF MATTER
Aristotle Believed matter to made of four basic substances:
Earth, Air, Fire, and Water
He thought that all other substances were made of a combination of the four basics.
Ancient peoples often used elements such as gold, silver, and mercury without realizing they were elements.
I. BUILDING BLOCKS OF MATTER
Scientists had been trying to identify all the “building blocks of matter” for hundreds of years.
Scientists often experimented with hundreds of substances as they searched for new elements.
They broke down common substances, such as salt, into their basic parts. (Proof that salt was not an element!)
I. BUILDING BLOCKS OF MATTER
With all the work of scientists, you may ask the question, “How do we classify these elements?”
Elements are grouped by their common properties and characteristics.
These groups are: Metals Nonmetals
I. BUILDING BLOCKS OF MATTER
Metal Characteristics include:
Shiny Thermal
conduction(heat) Electricity Malleability (Change
shape) Example:
Copper Iron Gold
I. BUILDING BLOCKS OF MATTER
Nonmetal Not shiny Heat and electricity to
not pass through easily
Malleability limited Examples:
Oxygen Carbon Sulfur
II. THE PERIODIC TABLE
Scientists tried to classify and arrange the elements into easy-to-read charts.
In 1869, Dmitri Mendeleev discovered that by arranging elements by the masses, the order came very naturally.
He also arranged the element by their unique properties in rows and columns.
Once he found where each known element should be placed, he left space for elements to be discovered later.
II. THE PERIODIC TABLE
Each element on the table has information to distinguish it for every other element.
These parts include: The Element’s name The Element’s symbol The Element’s number
II. THE PERIODIC TABLE
Let’s examine the period table on p. B12-B13. Let’s find:
Hydrogen Silver Uranium Neon Aluminum Potassium
III. ATOMS
The structure of an Atom: Atom: The smallest particle of an element that has the
properties of the element Nucleus: The center of an atom, where protons and
neutrons are located Proton: A particle in an atom that has a positive
electrical charge (+) Neutron: A particle in an atom that has no charge Electron: A particle in an atom that has a negative
electrical charge (-) On the board, copy down the hydrogen atom
diagram.
III. ATOMS
All atoms of an element have a particular number of protons.
The element’s number in the periodic table depends upon the number of protons found in the nucleus. Oxygen-Atomic Number 8 = 8 protons Gold- Atomic Number 79 = 79 protons