CHEMISTRY

Maybe I should be wearing goggles

Chemistry Pre-Test

1. What is matter?

2. Name the particles of the atom

3. List the CHARGES of each particle

4. How do we determine the Atomic Number of an element?

5. How do we determine the Atomic Mass of an element?

6. Name at least five (5) elements and their symbols

What is Matter?

• Anything that can be smelled, tasted, touched…

• Has mass and volume (takes up space)

• Matter exists in a state or phase

• Phases of matter include solid, liquid, gas, non-Newtonian, & plasma

Common Phases of Matter: Solid, Liquid, Gas

Non-Newtonian substances

sometimes behave like a solid and

sometimes like a liquid

Plasmas consist of freely moving charged particles, (electrons & ions)

It is perhaps the most common

phase of matter in the universe

Matter is made up of atoms… What’s an Atom?

• The word ATOM (átomos) was first used by the Greek philosopher Democritus

• Atom translates to “Indivisible”• It is the smallest particle characterizing an element• We can’t see the parts of atoms, even with modern

technology, so we have an Atomic Theory• A theory is a good, logical idea about something

but it hasn’t been proven to be true

Democritus460-370 BCE

Atomic TheoryIt’s thought that atoms are made of

these common particles:

• PROTON- has a positive Charge (P+)

• NEUTRON- has a neutral charge; has both positive and negative attributes (N=)

• ELECTRON- has a negative charge (e-)

Atomic Structure

Proton

Neutron

electron

Nucleus

Electron Clouds

Benfey’s Periodic Table 1960

Stowe Periodic Table 1988

Mayan Periodic Table 2001

Spiral Periodic Table 2005

Dufour Periodic Table

There is no single periodic table…

Most Common Periodic Table

• First organized using the known properties from other chemists like Stanislao Cannizzaro

• Dmitri Mendeleev created the most

commonly used table of elements in 1869

Mendeleev’s table 1869

Most Commonly Used Table

Period of elements

•Organized horizontally

•Indicates # of electron levels

Family of elements

•Organized vertically

•Indicates # of electrons in outer cloud

Nitrogen

2 75 N

14.0067

Atomic Number (# of P+)

# of e- in each electron cloud Atomic Mass (# of P+

& N=)

Elemental Name

Elemental Symbol (Often from Latin or Greek)

(1st letter is upper case, 2nd is lower case)

Q: How can I calculate the number of neutrons in an

element??

Elemental Names & Symbols

• Fe

• Iron; Latin Ferrum meaning “firm”

• Cu

• Copper; Greek for island of Cypress/ Cuprius

• Na

• Sodium; Natrium (Latin) meaning “soda”/ “salt”

• Ag

• Silver; from Latin Argentum meaning “bright”

More Elemental Names & Symbols

• Au

• Gold; (Latin) Aurum- Roman Goddess of dawn

• Hg

• Mercury; Greek Hydragyrium meaning ‘liquid silver’

• Pb

• Lead; Latin for Plumbum; origin of ‘plumber’

Element song?

http://www.privatehand.com/flash/elements.html

John DaltonSeptember 6, 1766 – July 27, 1844

• All matter is made of atoms

• Atoms of an element are identical

• Atoms are rearranged in reactions

Elements are individual atoms…

• When elements join together a compound forms

• Elements join forming molecules of a compound

• There several ways for molecules to form…

Covalent Bonding

•Atoms join together to form molecules of a compound through bonding

•Atoms “prefer” to have 8 e- in the outer cloud

•In order to become more stable, elements will share e-

•Water (H2O) is an example of covalent bonding

H H

O

Ionic Bonding

• Occurs with salts

• One element gives up an electron while another gains an electron

• In the case of Sodium Chloride, Na gives up an electron and Cl gains one

• This creates ions: the Na atom has a positive charge & the Cl atom has a negative charge

• Opposite charges attract and a compound is formed

Na Cl