1. The Nature of Matter
Chapter 2.1

2. Atoms: the building blocks of elements
Atom – smallest particle of an element that has the characteristics of that element
Structure effects their properties and chemical behavior

3. Atoms and their interactions
Element – a substance that can’t be broken down into simpler substances

4. Nucleus – center of the atom
Protons – positive charge
Neutrons – neutral charge
Electrons – around nucleus w/ negative charge

5. The structure of an atom

6. Electron Energy Levels
1st – can hold 2 electrons
2nd – can hold 8 electrons
3rd – can hold 18 electrons

7. An element is a pure substance consisting of only 1 type of atom
Elements and Isotopes
An element is a pure substance consisting of only 1 type of atom

8. Natural Elements in living things
Major elements in the human body: C, H, O, N
Make up more than 96% of the mass of the human body

9. Vital role in maintaining healthy cells
Trace Elements
Trace: Ca, P, K, S, Na, Cl, Mg, Fe, Zn, Cu, I, Mn, B, Cr, Mo, Co, Se, F
Vital role in maintaining healthy cells

10. Isotopes
Atoms that have the same # of protons, but a different # of neutrons
Named by # of protons & neutrons
Carbon-12 vs carbon-14

11. Isotopes are useful to scientists
Some nuclei of isotopes are unstable and break apart
Give off radiation
Can be used in medicine to diagnose or treat some diseases

12. 2 or more different atoms chemically combined in a specific ratio
Chemical Compounds
2 or more different atoms chemically combined in a specific ratio
Bonding – determined by electrons

13. Ionic bonds – electrons are gained or lost by individual atoms
atoms transfer electrons to form a bond
creates ions
Salt is an example

14. Atoms that gain or lose electrons have an electrical charge
Ions
Atoms that gain or lose electrons have an electrical charge
An ion is a charged particle made of atoms

15. Covalent bonds – electrons are shared – creates a molecule

16. A group of atoms held together by covalent bonds
Molecules
A group of atoms held together by covalent bonds
Water is an example

17. Van der Waals Forces
Intermolecular forces of attraction due to opposite charged regions on nearby molecules
Gecko’s foot/wall