PHYSCIE

force of attraction

force of attraction

A ___________________ is any type of force that causes objects to come together,even if those objects are not close to or touching each other

INTRAMOLECULAR

INTERMOLECULAR

Types of Forces of Attraction

INTRAMOLECULAR

are attractive forces between atoms in a molecule

INTERMOLECULAR

are attractive forces between molecules

weaker

Generally, intermolecular forces are ____________ than intramolecular forces

Metallic Bond

consists of positive ions and a sea of electrons, which is free to move about among the ions.

Metal + Metal
(+) + (-)

Ionic Bond

electrostatic attraction between two oppositely charged ion Ex: NaCl, MgO

Electrostatic Attraction
Metal + Nonmetal
COMPLETE TRANSFER OF ELECTRONS

COVALENT BOND

A bond that involves the sharing of electrons to form electron pairs between atoms.

Nonmetal + Nonmetal
Sharing of Electrons

Ex: H₂, CO₂, H₂O

POLAR (UNEQUAL SHARING DUE TO ELECTRONEGATIVITY, USUALLY DIFFERENT ATOMS, PARTIAL IONIC CHARGES)

NON-POLAR (EQUAL SHARING, USUALLY SAME ATOM, NO CHARGES)

COVALENT BOND (Based on Bond Polarity)

Difference in Electronegativity

Dipole Moment

Ways to Determine the Bond Polarity

Difference in Electronegativity

The difference between the electronegativity of the atom sin a bond

Dipole Moment

the product of the charges atone center multiplied to the distance between the positive and the negative centers

Electronegativity

The ability of an atom to attract itself to the electrons in a chemical bond.

high

Elements with ______ electronegativity have a greater tendency to attract electrons than the elements with low electronegativity

NON-POLAR COVALENT

If the electronegativity difference has a value of <0.5

POLAR COVALENT

If the electronegativity difference has a value of 0.5 - 1.8

IONIC

If the electronegativity difference has a value of: >1.8

Dipole Moment

occur when there is a separation of charge. A quantitative measure of the polarity of a bond.

Dipole Moment

can be predicted using the difference in electronegativity of the atoms in a bond. The higher the difference in electronegativity the larger the dipole moment.

The shift of electron density is symbolized by placing a crossed arrow above the Lewis structure to indicate the direction of the shift.

Ion- Dipole Bond

attractive forces between an ion and a polar molecule
Ex: H₂O and Na+

Dipole

refers to a bond or molecule whose ends have opposite charges

Van der Waals Forces

Intermolecular Forces

Distance Affects Their Strength

Strong to Weak

Hydrogen Bonding -> Dipole-Dipole Interaction -> London Dispersion Forces

Three Types of VDW Forces

London Dispersion

Temporary attractions between molecules occurs when the electrons around a molecule are unevenly distributed causing a temporary dipole.

(NON POLAR + NON POLAR)
(NON POLAR + POLAR)

basta may pair na non polar

Dipole- Dipole Bond

occurs between polar covalent molecules where one part of the molecule has a partial positive charge and the other part a partial negative charge

(POLAR + POLAR)

Hydrogen Bond

attraction between a highly electro negative atom (N, O, and F) and a hydrogen atom Ex: H₂O molecule

CHECK MO UNG N, O ,F

(POLAR + POLAR) rin pero UNG BOTH SIDE DAPAT MAY N O F

If the interaction occurs between a hydrogen atom that is bonded to a nitrogen, oxygen, or fluorine atom, and a separate nitrogen, oxygen, or fluorine atom

1. Write Symbol

2. Ex: Carbon, 4th group so 4 valence electrons

3. Draw dots counter clockwise (to the left)

Follow rule of octaves

Writing Lewis Structure

Weaker

VDW forces are __________ than intermolecular forces.

Cosmology

study of how the universe began, how it continues to exist, and how it will end.

Biblical

Buddhist

Hindu

Chinese

Religious Cosmology

BIG BANG THEORY

•In 1927, George Lemaitre proposed that about 13.8 billion years ago, all current and past matter in the universe came into existence from a small ball with infinite density and intense heat known as Singularity

Singularity

small ball with infinite density and intense heat known as ______________

1927

George Lemaitre

•In ______, ___________________ proposed that about 13.8 billion years ago, all current and past matter in the universe came into existence from a small ball with infinite density and intense heat known as Singularity

13.8 billion years ago

How long was the Big Bang years ago?

George Gamow (1961)

Manhattan Project

It was refined, publicized, and popularized by________________________ ,one of the _________________________ scientists who took part in creating the atomic bomb during World War II, who named it the Big Bang Theory.

HOW DO WE KNOW THE BIG BANG HAPPENED?

Edward Hubble (1929) noticed that galaxies around us seemed to be moving away from us.

Hubble's Law states that the more distant the galaxy, the faster it is moving away from us.

Edward Hubble

________________________ (1929) noticed that galaxies around us seemed to be moving away from us.

Hubble's Law

_________________________ states that the more distant the galaxy, the faster it is moving away from us.

EXPANSION

BIG BANG IS NOT AN EXPLOSION BUT AN _______________________

Arno Penzias and Robert Wilson

__________________________________ provided evidence through the discovery of cosmic microwave background of the Big Bang (1965)

cosmic microwave

Arno Penzias and Robert Wilson provided evidence through the discovery of ______________________________ background of the Big Bang (1965)

NUCLEOSYNTHESIS

The creation of new atomic nuclei, the centers of atoms that are made up of protons and neutrons.

NUCLEAR FUSION

It is the process by which light nuclei fuse together to form a heavier nucleus.

NUCLEOSYNTHESIS

NUCLEAR FUSION

FORMATION OF LIGHT ELEMENTS

STELLAR NUCLEOSYNTHESIS

It is the process by which heavy elements are created within stars due to combination of the protons and neutrons from the nuclei of lighter elements.

Stars live in a balance between two opposing forces: gravity, and thermal pressure of nuclear fusion

As the hydrogen in the core gets used up, the star begins to convert helium into heavier elements:Lithium to Iron

Heavier elements cause the core to become dense,increasing its gravitational pull. Fusion reactions also release less energy .

When the core reaches a critical density, the star's core collapses in a matter of seconds,

The gas that was rushing in at incredible speeds strikes against the surface of the neutron star.It rebounds in a massive shock wave that ends in a huge explosion

PROCESS OF SUPERNOVA

NUCLEUS

ORBIT

PROTON

ELECTRON

NEUTRON

SUBATOMIC PARTICLES OF AN ATOM

Nucleus

The central _______________ consists of protons and neutrons. It containing almost all the mass of the atom.

Nucleus

the ____________ of an atom is very
small compared
to the size of the
atom.

Atomic Mass

Atomic mass/weight-average mass of different isotopes of an element

Mass Number

combined number of protons and neutrons in a particular atom or isotope

Isotopes

the same number of protons but different numbers of neutrons

Mass number (A)

= number of p + number of n
= Z + number of n

Atomic Number (Z)

= number of p

Number of neutrons

= A - number of protons

1 - Boiling "soup" with electrons, quarks and other elementary particles. Space cools off rapidly. Quarks form protons and neutrons.

2 - Universe-superhot fog.
Heated protons and electrons hinder the emission of light. Light elements created like deuterium, lithium, helium

3 -Protons, electrons, neutrons combine and form atoms. Primarily hydrogen and helium atoms

4 - Galaxy formation era. Hydrogen and helium atoms begin to form giant clouds that will become galaxies and stars

5 - First dying stars produce heavy elements which turn into new stars and planets Sun ~ 4.6 billion years old
Solar System ~ 4.5 billion years old
Milky Way - 13.2 billion years old

PHASES OF BLACK HOLE

1

Boiling "soup" with electrons, quarks and other elementary particles. Space cools off rapidly. Quarks form protons and neutrons.

2

Universe-superhot fog.
Heated protons and electrons hinder the emission of light. Light elements created like deuterium, lithium, helium

3

Protons, electrons, neutrons combine and form atoms. Primarily hydrogen and helium atoms

4

Galaxy formation era. Hydrogen and helium atoms begin to form giant clouds that will become galaxies and stars

5

First dying stars produce heavy elements which turn into new stars and planets Sun ~ 4.6 billion years old
Solar System ~ 4.5 billion years old
Milky Way - 13.2 billion years old

Antoine Lavoisier (1743 - 1794)

- Published Elements of Chemistry in 1789

• Included a list of "simple substances"(which we now know to be elements)

• Formed the basis for the modern list of elements

- Only classified substances as metals or nonmetals

Johann Döbereiner (1780 - 1849)

Classified elements into "triads"

• Groups of three elements with related properties and weights

Began in 1817 when he realized Sr was halfway between the weights of Ca and Ba and they all possessed similar traits

Döbereiner's triads:

• Cl, Br, I
S, Se, Te
• Ca, Sr, Ba
Li, Na, K

John Newlands (1837 - 1898)

Law of Octaves (1863)
• Stated that elements repeated their chemical properties every eighth element
• Similar to the idea of octaves in music

Dmitri Mendeleev (1834 - 1907)

Russian chemist ("The father of the periodic table")

- Arranged elements based on accepted atomic masses and properties that he observed

- Listed elements with similar characteristics in the same family/group• Left blank spots for predicted elements

Henry Moseley (1887 - 1915)

English physicist
- Arranged elements based on increasing atomic number
• Remember: atomic number = # of p+ in nucleus- Periodic table looked similar to Mendeleev's design since as atomic number increases, so does the atomic mass

Periodic

occurring at regular intervals
- Relates to trends on the periodic table of elements

Modern Periodic Law

When elements are arranged in order of increasing atomic number, there is a periodic repetition of their properties
• Just like Mendeleev suspected!!

Periods

"Horizontal Rows"

•Groups (or Families)

"Vertical Columns"

periodic

Valence electrons are _______________

GROUPS

_______________ have similar valence electron configurations

Group 1 = Alkali Metals

Located in Group 1 (except Hydrogen)
- Extremely reactive
• Want to lose 1 e- to become "noble gas-like" (positive)

Group 2 = Alkaline Earth Metals

- Also very reactive
- Both Group 1 & 2 occur naturally as compounds not element

Group 17 = Halogens

Very active nonmetals
• Want to gain 1 e- to become like a noble gas (negative)

Group 18 = Noble Gases

- Sometimes called "inert gases" since they generally don't react
• Mainly true, but not always (Kr, Xe will react sometimes)
• Have a full valence shell (8 e-)

Transition Metals

- Located in the center of the Periodic Table
- 10 elements wide ("d" orbitals)
- Semi-reactive, valuable, crucial to many life processes

Lanthanides and Actinides

- Located at the bottom of the Periodic Table
- 14 elements wide ("f" orbitals)
- Some are radioactive, though not all
- Lanthanides = Period 6 (4f)
- Actinides = Period 7 (5f)

Electronegativity

Ability of an atom to pull e-
towards itself
- Increases going up and to the right
• Across a period
➔ more protons in nucleus =more positive charge to pull electrons closer
• Down a group ➔ more electrons to hold onto =element can't pull e- as closely

Atomic Radius

Distance between the nucleus and the furthest electron in the valence shell
- Increases going down and to the left
• Down a group ➔ more e- = larger radius
• Across a period ➔ elements on the right can pull e- closer to the nucleus (more electronegative) = smaller radius
• <b>Remember</b>- LLLL → Lower, Left, Large, Loose

Ionization Energy

- Energy/Strength required to remove an e- from the ground state
-Resistance of e- ripped off

- 1st I.E. = removing 1 e-, easiest
- 2nd I.E. = removing 2 e-, more difficult
- 3rd I.E. = removing 3 e-, even more difficult

Ionization Energy

Increases going up and to the right

- Down a group ➔ more e- for the nucleus to keep track of = easier to rip an e- off
- Across a period ➔ elements on the right can hold electrons closer (more electronegative) = harder to rip an e- of

Ionic Radius

Radius of an atom when e- are lost or gained
→ different from atomic radius

- Ionic Radius of Cations•
Decreases when e- are removed
- Ionic Radius of Anions
• Increases when e- are added

CATIONS

• ____________ are SMALLER than the atoms from which they are formed.

• Size decreases due to increasing the electron/proton attraction.

ANIONS

• __________________ are LARGER than the atoms from which they are formed.

• Size increases due to more electrons in shell.

Metallic Character

How "metal-like" an element is
• Metals lose e-
- Most Metallic: Cs, Fr
- Least: F, O
- Increases going down and to the left

Atomic Radius

Metallic Character

Increases going down

Increases to the left

Ionization Energy

Electronegativity

Ionic Radius

Increases going up

Increases to the right

Cs, Fr

MOST METALLIC ELEMENTS

F, O

LEAST METALLIC ELEMENTS

PARTICLES MUST COLLIDE

SUFFICIENT ENERGY

CORRECT ORIENTATION

COLLISION THEORY REQUIREMENTS

COLLISION THEORY

PARTICLES ARE IN CONSTANT MOTION THAT COLLIDES AND MAY RESULT TO CHEMICAL REACTION

1. Substances or particles of reactants must PHYSICALLY COLLIDE WITH ENOUGH ENERGY.

2. Particles are in CORRECT ORIENTATION.

2 FACTORS OF COLLISION THEORY

TEMPERATURE

RATE OF REACTION IS DIRECTLY PROPORTIONAL TO TEMPERATURE CONCENTRATION PRESSURE

REFERS TO HOW COLD OR HOT A CERTAIN SUBSTANCE IS

CONCENTRATION

DIRECTLY PROPORTIONAL

REFERS TO THE NUMBER OF PARTICLES PRESENT IN A GIVEN VOLUME OF SOLUTION

SURFACE AREA

DIRECTLY PROPORTIONAL

MEASURES OF HOW MUCH EXPOSED AREA A SOLID OBJECT HAS WHICH IS EXPRESSED IN SQUARE UNITS

CATALYSTS

IT IS A SUBSTANCE THAT HASTEN THE REACTION WITHOUT BEING CONSUMED BY THE REACTION.

IT LOWERS THE ACTIVATION ENERGY REQUIREMENT IN ORDER FOR IT TO FORM NEW PRODUCTS.

TEMPERATURE (DP)

CONCENTRATION (DP)

SURFACE AREA (DP)

CATALYST

PRESSURE (DP)

FACTORS THAT AFFECT THE RATE OF CHEMICAL REACTION

PHYSICAL CHANGE

A change that does not alter the identity of a substance; it remains the same, though it may look or feel different, and does not produce a new substance.