1. LIFE ON MARS
The Chemistry of Life

2. What does matter look like on the most basic level?
Atom – From the Greek word atomos, which means “unable to be cut”; Very small in size
smallest particle of matter
Cannot be broken down any smaller
Made up of protons, neutrons and electrons

3. Atomic Structure
The atomic nucleus is located at the center of the atom and is made of:
Subatomic Particles
Proton (+) positively charged
Neutron (0) no charge
Electrons
Move around the nucleus in energy levels
(-) negatively charged and smallest
Electrons are in constant motion outside the nucleus

4. Sketch an Atom

5.
How small is an atom?

6. Most of the atom is empty space
If the atom was the size of this classroom, the nucleus would be the size of a grain of sand in the middle!!

7. Elements – An element is a pure substance made of one type of atom
More than 100 are known
Only about 24 are commonly found in organisms
ATOMIC NUMBER = # or protons
Ex. Carbon has 6 protons, so it has an atomic number of 6
Examples: Oxygen Hydrogen, and Carbon
Mass number= the sum of the protons and neutrons
Ex. Carbon has 6 protons and 6 neutrons; the mass number of carbon is 12

8. I made the PERIODIC TABLE !
I am Dmitri Mendeleev!
I made the PERIODIC TABLE !

9. What is the PERIODIC TABLE?
Shows all known elements in the universe.
Organizes the elements by chemical properties.

10. How do you read the PERIODIC TABLE?

11. Elements are represented by a 1 or 2-letter symbol (see p. 1086)
Elements are represented by a 1 or 2-letter symbol (see p.1086). Be familiar with the following elements:
C = carbon
O = oxygen
H = hydrogen

12. What is the ATOMIC NUMBER?
The number of protons found in the nucleus of an atom Or
The number of electrons surrounding the nucleus of an atom.

13. What is the SYMBOL?
An abbreviation of the element name.

14. What is the ATOMIC WEIGHT?
The number of protons and neutrons in the nucleus of an atom.

15. How do I find the number of protons, electrons, and neutrons in an element using the periodic table?
# of PROTONS = ATOMIC NUMBER
# of ELECTRONS = ATOMIC NUMBER
# of NEUTRONS = ATOMIC _ ATOMIC
WEIGHT NUMBER

17. What is an ELEMENT? A substance composed of a single kind of atom.
Cannot be broken down into another substance by chemical or physical means.

18. What is a COMPOUND?
A substance in which two or more different elements are CHEMICALLY bonded together.

19. Examples:
H2O is made of 2 Hydrogen atoms and 1 oxygen;
NaCl is made of 1 Sodium and 1 chlorine atom
2. The chemical properties of a compound are different from the elements that form the compound

20. What is a MIXTURE?
Two or more substances that are mixed together but are NOT chemically bonded.

21. Element, Compound or Mixture?

22. a. solutions – when all components are evenly spread in water
Two types of mixtures:
a. solutions – when all components are evenly spread in water
solute - substance that is dissolved
solvent – the substance that dissolves the solute (ex: water)
b. suspensions – when all components are not completely dissolved in water

23. Element, Compound or Mixture?

24. Element, Compound or Mixture?

25. Element, Compound or Mixture?

26. Element, Compound or Mixture?

27. Element Composition of…
Earth
Mars
Oxygen 47%
Silicon 27%
Aluminum 8%
Iron 5%
Calcium 4%
Oxygen
Silicon
Iron
Magnesium 
Aluminum 
Calcium