1. Classifying Matter
Take out a pencil and the following vocabulary cards:
Atom
3. Element
9. Nucleus
10. Proton
11. Neutron
12. Electron
13. Electron cloud
14. Atomic number
15. Isotope
15. Ion
18. Anatomy of an Atom
19. Possible changes in Atoms
21. Chemical bond
4. Molecule
2. Substance
5. Compound
6. Mixture
7. Heterogeneous mixture
8. Homogeneous mixture

2. 1. Atom Building blocks of all matter
The study of atoms and their smaller particles is called the atomic theory
Many different types of atoms (elements)
Mostly empty space
In natural processes, atoms are not destroyed, they are recycled
In a neutral atom, the number of protons is the same as the number of electrons

3. 1. Atom

4. Made up of atoms (~100 trillion/cell)
Atoms vs. Cells
Atoms
Cells
Have a nucleus
Building blocks
of everything
Have a nucleus
Building blocks
of every living thing
Made up of atoms (~100 trillion/cell)

5. Nuclear Fusion
The nucleus of one atom combines with the nucleus of another atom
Hydrogen to Helium
The 1 proton in the hydrogen atom combines with the 1 proton in another hydrogen atom
New atom has two protons

6. How Atoms Formed
The Big Bang Hydrogen and helium form stars Stars became more compact and hotter in the core (enough energy for nuclear fusion) At least 25 million degrees F for helium At least 180 million degrees F for carbon, oxygen, etc. Stars die and explode releasing elements and creating higher level new elements

7. Synthetic Atoms Created artificially (man-made)
Some may exist in the universe, but not on Earth
Most don’t last long (some exist for only a split second)
Few useful synthetic atoms
Plutonium: creates energy, used in nuclear weapons, highly toxic

8. 18. Anatomy of an Atom

9. 9. Nucleus
Region at the center of an atom that contains most of the mass of the atom
Composed of protons and the neutrons
Always has a positive charge (positive proton + neutral neutron)

10. 10. Proton Positively charged particle in the nucleus of an atom
Number of protons determines the identity of every element
# of protons = atomic number

11. 11. Neutron Uncharged particle in the nucleus of an atom
The number of neutrons on an atom is the atomic mass – the atomic number
Usually the heaviest part of an atom

12. 10. Electron
Negatively charged particle that occupies the space in an atom outside the nucleus
Electrons furthest from the nucleus have the most energy
Electrons can travel in any direction around the nucleus

13. 10. Electron Cloud
The region surrounding an atom’s nucleus where one or more electrons are most likely to be found
Contains mostly empty space
Electrons can be located closer to the nucleus or further out

14. 18. Anatomy of an Atom

15. 3. Element Substances made of only one kind of atom
Identity of an element depends on the total number of protons it has (its atomic number)

16. 14. Atomic Number
The number of protons in the nucleus of an atom of an element
Every element in the periodic table has a different atomic number
You can identify an element if you know either its atomic number or the number(s) of protons its atoms have

17. 15. Isotope
One of two or more atoms of an element having the same number of protons, but a different number of neutrons
In nature, most elements are found as mixtures of isotopes
Isotopes of an atom have the same chemical behavior

18. 16. Ion
An atom that has a charge because it has gained or lost electrons
Cation – ion with a + charge - remove electron(s)
Anion – ion with a - charge – add electrons

19. 19. Possible Changes in Atoms
Neutral Atom
Change
# of Particles
Type of Atom
Element Symbol
6 protons
6 neutrons
6 electrons
+1 neutron
7 neutrons
Isotope C
+1 electron
7 electrons
Ion C-
+1 proton
7 protons
New element - nitrogen N

20. 21. Chemical Bond A force that holds two or more atoms together
Negatively charged electrons are attracted to the positively charged nucleus
Electrons closer to the nucleus are more strongly attracted to the nucleus and vice-versa
The outermost electrons can be attracted to another atom’s nucleus
This attraction creates a chemical bond between the atoms

21. 4. Molecule
Two or more atoms that are held together by chemical bonds and act as a unit
Ex. Table sugar – C12H22O11
One grain of sugar contains trillions of these molecules
Give substances their identity

22. 2. Substance Matter with a composition that is always the same
Bonded at atomic level
Always contains the same kinds of atoms in the same combination
All elements are substances

23. 3. Element Substances made of only one kind of atom
Identity of an element depends on the total number of protons it has (its atomic number)

24. 5. Compound
Substance made of two or more elements that are chemically joined in a specific combination
Ex. H2O – water always has two hydrogen atoms and one oxygen atom
Changing the composition of a compound changes it into a new compound with new properties (ex. H2O2 – hydrogen peroxide)
Each has a chemical formula

25. 6. Mixture Matter that can vary in composition Not chemically bonded
Can be physically separated
Ex. Salt water – you can change the amounts of salt or water and it’s still salt water
Can be any state of matter

26. 7. Heterogeneous mixture
Mixture in which the substances are not evenly mixed
Different substances are visible by unaided eye or under microscope
Can be separated by physical separation, magnets (if part of it is magnetic), etc.
Hetero - different

27. 8. Homogeneous mixture
A mixture in which two or more substances are evenly mixed, but not bonded together
Also known as a solution
Can be separated by boiling or evaporation
Can’t tell the differences between substances under a microscope (where one begins and the other ends)
Ex. Brass, lemonade and air

28. Combining Atoms Concept Map
Element
Homogeneous mixture
Compound
Heterogeneous mixture
Mixture
Substance
Chemical
Physical
Solution