1. Matter

2. Matter
Matter is everywhere. It is anything that has mass and takes up space.
Examples: books, paper, oxygen, soup, hands, etc.
All matter is made of elements.
Elements are materials that cannot be broken down into anything simpler.
There are more than 112 elements.

3. Metals, nonmetals, and metalloids
All elements are metals, nonmetals, or metalloids.
Metals – shiny, conduct heat and electricity, and bend easily
Examples: Silver, gold, platinum, titanium
Nonmetals – dull, poor conductors of heat and electricity, and brittle
Examples: oxygen, hydrogen, helium
Metalloids – some properties of metals, some properties of nonmetals
Examples: silicon, arsenic

4. Atoms
An atom is the smallest unit of an element that retains the properties of that element.
John Dalton, in 1803, proposed that elements are made of tiny particles. These particles we know today as atoms.

5. Inside atoms Atoms are made of even smaller particles.
Atoms contain protons, electrons, and neutrons.

6. Protons Protons- a particle with one unit of positive electric charge.
Atomic number- the number of protons in an atom.
The atomic number determines which element it is.

7. Neutrons
A neutron is a particle with no electric charge. It is neutral.

8. Electrons Electrons are particles with a negative charge.
They move within the space outside the nucleus.

9. Atomic Mass
If you add up the mass of all the protons and neutrons in an atom, you have found the atomic mass!

10. Compounds and molecules
A compound forms when two or more elements combine
Compounds have properties that are different from the original elements!
Examples: salt (sodium chloride) and rust (iron oxide)
A molecule forms when two or more atoms join together and share electrons
Example: water

11. What properties are used to classify books in a library?
They are classified by:
Fiction and nonfiction
Nonfiction by subject matter
Fiction by author’s last name

12. What properties are used to classify animals?
Vertebrates or invertebrates
How they reproduce
Cold-blooded or warm-blooded

13. How do you think elements are classified?
They are classified according to their properties.

14. What properties are used to classify elements?
They are classified by:
Whether they are reactive
Whether they are solid, liquid, or gas at room temperature
Whether they are metal, metalloid, or nonmetal

15. The Periodic Table of Elements
Each element has a symbol. The symbols for most elements are one or two letters. The first letters are always capital. Second letters are never capitals.
In 1869, Dmitri Mendeleev made element cards. He ordered the elements from lightest to heaviest. He found that the elements’ properties repeat in cycles. He made the cycles of elements into rows in a table. Mendeleev’s table is called a periodic table because the properties repeat in cycles.

16. The periodic table

18. How do the particles in your desk move?
They vibrate in place.
How do the particles of water from the drinking fountain move?
They flow past each other.
How do particles in the air move?
They move past each other very easily.

19. Forms of Matter
Three states of matter: solid, liquid, and gas

20. Forms of Matter
Solids have a definite shape and a definite volume no matter what container they are in. Can only change by breaking or heating etc. Particles have very little freedom to move

21. Forms of Matter
Liquids have a definite volume, but not a definite shape, Shape depends on container. Particles move more freely than in a solid.

22. Forms of Matter
Gas particles are not close together and can move very freely. Gas does not have definite volume or definite shape.