Standard 1.1Common Origins

All matter in the universe has…..

• Common Origins

• Therefore, all matter in the universe and on earth is composed of…

• The same type of elements

The most abundant element in the universe is…..

• Hydrogen

• At first the only elements were hydrogen and helium.

Fusion Reactions create the heavier elements

• Basically- Fusion of lighter elements formed heavier elements.

The most common element in the universe is

• hydrogen, • and the heavier elements are less common. • The earth has more of the heavier elements

in its crust than the universe does.

Hubble

• Hubble was an astronomer who discovered that our universe is expanding.

• Billions of years ago many believe a “big bang” gave rise to this expanding universe.

Scientists in the Bell laboratory in the 1965 detected “noise” from space in a radio telescope

• The noise remained constant no matter which direction they scanned.

• They suspected that it came from bird droppings on the antenna,

• but after a careful cleaning the noise remained.

• They discoved waves in space (specifically microwaves)

• What important discovery did they make that supports the Big Bang theory?

• They accidentally discovered radiation leftover from the Big Bang.

Supporting this theory

• The Big Bang Theory describes the formation of the matter in the universe. Why do scientists support this theory?

• Evidence from starlight shows that the universe is still expanding.

How do we see what elements are in the stars?

• by studying the atomic line spectra in the star’s light.

Helium was discovered on the sun in 1868, almost 30 years before it was discovered here on the earth. How could that be possible?

• Investigation of light from the sun revealed a spectrum not yet found in known elements.

Standard 1.2

• Atomic Models and their limitations.

Dalton – atomic theory

• Atom is small and indivisible, • All atoms of an element are identical• Atoms can be rearranged -> compounds and

chemical reactions• Atoms of any one element are different from

those of another element

2. Thompson

• Also called– • plumb pudding –

Thompson’s experiment involved the

• Cathode Ray• Discovered the electron. • Mass 0, charge -1

Rutherfords experiment is called:

Gold foil experiment

A beam of alpha particles is shot at gold foil, most of the beam goes all the way through, but some of the beam is deflected.

2. Rutherford model

• Most of an atom’s mass in the center (nucleus) and is positively charged

• Atoms are mostly empty Space

3. Bohr Model

• Electron’s orbit the nucleus

4. The currently agreed upon model Quantum mechanical model

• Electrons exist in a cloud, within energy levels and travel in waves, • Also called the mathematical model because it involves

probabilities when trying to figure out where the electron is.•

Proton, neutron and electron – what is the mass, charge and where located?

NucleusProtons

+1 chargeMass number of 1

NeutronsNeutral chargeMass number of 1

Electron cloudElectrons

-1 chargeMass number of 0Number of electrons = number of protons

How do you identify an atom?

The atomic numberWhat is this?The number of protons

What are these elements and what are there atomic masses and there molar masses?

Switch to over head

• Molar mass• Grams to moles and moles to grams• Do the ones in your packet.

Relate the mass and number of atoms to the gram-sized quantities of matter in a mole.

• Average atomic mass = • One mole • Which = 6.02 x 1023 atoms / mole

Switch to overhead

• Do the ones in your packet

Standard 1.3

• Correlate atomic structure and the physical and chemical properties of an element to the position of the element on the periodic table.

Similar column/Group/family

• Similar properties• Because• They have the same number of

valence electrons

XAZ

Mass number

Atomic number

Al27

13

Aluminum with 13 protons & 14 neutrons

Can also be written as Al-27

Symbols – With atomic number and mass

number

Mass number

• The number of Protons + neutrons.• The atomic number• Number of protons• The number of protons equals the number of

electrons in a neutral atom.

Isotopes

• Atoms that have the same number of protons but different number of neutrons

How many protons, neutrons and electrons in Neon isotopes?

• Ne – 20

• Ne – 21

• Ne - 22

All have

10 protons and

10 electrons

10 Neutrons

12 Neutrons

11 Neutrons

Ne2010 Ne22

10Ne2110

Isotopes – You do

• How many protons, neutrons and electrons in• Oxygen – 16• Oxygen – 18• Oxygen - 19

Isotopes are chemically alike because

• They have the same number of protons and electrons.

Periodic Table -

stuff

First periodic table

• Dmitrii Mendeleev

• Organized by atomic mass

• Current one is organized by?

• Atomic number

Metals

Lose electrons (+ charge) cations, conductive (heat and electricity),

malleable, ductileluster

Metals

Metals get more reactive as you move to the left and

down a group

Nonmetals

Gain electrons (-charge) anions Brittle

InsulatorsNon conductors

Nonmetals

Non metals – More reactive

up and to the right

Metalloids

Properties of both metals and non metals

Semi-coductors