1. Introduction to Atoms

2. Chemistry Atoms are the foundation of chemistry
Chemistry: study of matter, its properties, and how and why substances combine and separate
Atoms foundation  basic building blocks

3. Atoms Nucleus  protons and neutrons Protons (+) Neutrons (0)
Defines the element (atomic number)
# of Protons = Atomic Number
Neutrons (0)
Neutral does not have a charge
Atomic Mass (Mass number)
Mass of protons + neutrons
same size
Each of them weigh 1 AMU (Atomic Mass Unit)
Atom means uncuttable
The period table is written in order of the atomic number and the a.n. is the # of protons
Carbon 12 has 6 protons and 6 neutrons (keep in mind the # of n and e can change but p cannot
Carbo 14 has 6 proton and 8 n
So if we have a neutral carbon 12 atom and it has 6 p it also has 6 e
Atomic Mass (mass of p and n)
AMU = 1x67x10-27 of a kg

4. Atoms Electrons Electron shell/ cloud Negative charge
Do not contribute to atomic mass
Electron shell/ cloud
Valence Electrons – Electrons in the outer most shell
Levels in electron shell
2, 8, 18, 32
2(n^2)
N is shell # the answer will let you how many electrons it can hold
F3_30lUE
1 proton = 1836 electrons
What’s the .001?
Average of all the types of C (12, 13, 14) average weight

5. Isotopes
Atoms with the same number of protons but a different number of neutrons
C12  C13, C14
He2  He3, He4
Isotopes will chemically act the same way but have differences in nuclear stability
?v=wMx1l86XFLU
Isotopes like siblings
Differences in chemical stability  able to undergo a nuclear reaction more easily than others

6. Chemical Bonds 1. Ironic Bond  one atom transfers an electron
The other atom gains the electron
Atom that loses a electron is called a cation (+ charge)
Atom that gains the electron is called an anion (- charge)

7. Chemical Bonds Covalent Bond: Sharing of electrons between two atoms.
Two types of covalent bonds: polar and nonpolar
The most common bond in organic molecules

8. The Periodic Table of Elements
Created by Dmitri Mendeleev
In 1868
First the periodic table was arranged by the elements atomic mass not atomic number
m/periodictable_0_click_common. html
Mendeleev found that when he arranged the table by atomic mass, atoms did not share similar traits

9. Organization of the Periodic Table
Used to predict properties of elements by it’s location in table
Arranged by atomic number.
Atomic number increases from left to right

10. Periods Horizontal rows
Rows that run from left to right
A Period contain a series of different elements
Properties change from left to right
Ex. From left to right you have
Highly reactive metals
Less reactive metals
Metalloids
Nonmetals
7 Periods

11. Groups Vertical columns https://www.youtube.com/watch ?v=sS3cIK9jlB8
Also known as families
Consist of elements with similar characteristics
Group 1: are metals that react violently with water
Group 2: react with water slowly or not at all
Group 17 reacts violently with Group 1
Group 18 rarely react at all
18 Groups 6M
?v=sS3cIK9jlB8

12. How Elements Form in Stars
Where do elements come from?
Stars are made up from mostly H
Hydrogen exists at extremely high temperatures and pressures (15 million degrees C)
At these extremes, matter does not exist as a solid, liquid, or gas.
Plasma  gas-like mixture without electrons
Collection of nuclei of atoms

13. How Elements form in Stars
Atomic Nuclei are positively charged
Usually positive charges repel one another
In stars, the pressure is so high  nuclei are squeezed close together and collide  nuclear fusion
Nuclear fusion  in stars occurs on a huge scale  combines smaller nuclei into larger nuclei which creates heavier elements
As He builds up in the suns ore, other fusion reactions occur. Over time, these fusion reactions form nuclei of slightly heavier elements such as C, N, O
Ex. In the sun, isotopes of H fuse producing nuclei of He
The energy from this reaction is the suns source of energy

14. Molecules and Compounds
Molecule: formed when two or more atoms join together chemically
Compound: molecule that contains at least two different elements
All compounds are molecules but not all molecules are compounds
H2, N2, O2  Molecules (same element)
H20, NaCl, C6H12O6  Compounds (molecule and compound)