• the nucleus of an atoms splits into smaller nuclei

• Formation of light elements

• Hydrogen to helium (1-2)

• Formation of elements heavier than iron

• Cobalt to Uranium (26-92)

• Formation of manmade elements

• Neptunium to Oganesson (93-118)

• Formation of heavy elements

• Lithium to Iron (3-26)

• Proposed that the atom is in a solid, sphere model

• Said that atoms are indivisible

• Discovered the planetary model most widely known as orbitals

• Said that the orbital of ane element would vary according to its size; the greater the atomic number, the greater the orbital number

• Proposed the plum pudding model

• Suggested that the atom was composed of positively charged sphere in which the electrons are loosely embedded on its surface

  • Discovered negatively charged electrons

• Proposed the nuclear model

• Discovered positively charged protons through the process of the Alpha Scattering Experiment

• Proposed the quantum model

• Explained the odds of finding the position of an electron through mathematical descriptions which are called quantum numbers

• Discovered the neutrons

• Positively charged protons and neutral neutrons bound together as the atom’s nucleus, with negatively charged electrons occupying energy levels surrounding the nucleus

• changes the structure of the nucleus

• does not change the structure of the nucleus

(High-energy) helium nuclei consisting of two protons and two neutrons

(High-energy) electrons

Nuclei of hydrogen atoms

Particles with the same mass as an electron but with 1 unit of positive charge

Very high-energy electromagnetic radiation

Particles with a mass approximately equal to that of a proton but with no charge

• A neutron will bind or fuse with another element

• reactant

• Addition of an alpha particle through fusion

• Reactant

• The neutron appears after the division or fission of a bigger element

• Product

• Loss of an alpha particle through fission

• Product

• Conversion of a proton in a nucleus into a neutron along with the release of a proton

• Loss of a beta particle through fission

• Product

• Drawing of an electron through fission into an atom’s nucleus

• Reactant

• Emission of gamma rays

• Electrons should always occult the orbitals with lower energy before those with higher energy

  • S = 2

  • P = 6

  • D = 10

  • F = 14

• The most stable arrangement of electrons in subshells is the one with the greatest number of parallel spins.

• No two electrons in an atom can possess the same set of quantum numbers

• Quantum numbers are numerical values assigned to elements based on their electron configuration

• Each element has a unique set of quantum numbers, distinguishing it from others

• - Represents the electron shells or energy levels of an atom, ranging from 1 to 7

• - It indicates the size of the atom, with higher values corresponding to larger shells

• The principal quantum number refers to the outermost electron shell of an atom

• represents the orientation of the electron orbital and is based on the orbital diagram

• It indicates the spatial orientation of the orbital within the subshell

• epresents the shape of the electron orbital and can take values from 0 to 3

  • It determines the shape of the orbital:

• It involves the spin of the electron within an orbital

• An upward arrows represents a spin of +½

• A downward arrows represents a spin of -½

• Refers to the vertical columns in the periodic table

• Elements within the same group have similar chemical properties

• Elements in the same group have the same number of valence electrons

• Contains elements such as beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), etc. 

• Also known as the alkaline earth metals

• These elements have two valence electrons and are reactive but less so than Group IA elements

• These are transition metals located in the center block of the periodic table

• They include elements such as iron (Fe), copper (Cu), zinc (Zn), and silver (Ag), etc.

• Transition metals exhibit variable oxidation states and often form colorful compounds

• Contains elements such as hydrogen (H), lithium (Li), sodium (Na), potassium (K), etc.

• Also known as the alkali metals

• These elements have one valence electron and are highly reactive

• Refers to the horizontal rows in the periodic table

• Each period represents the energy levels or electron shells occupied by the elements

• Elements in the same period do not necessarily have similar properties, unlike elements in the same group

• Composed of two or more atoms bonded together

• Treated as a single unit with an overall charge

• Comprising two or more elements that are chemically bonded together

• A compound won’t form unless its constituent elements are chemically bonded to each other.

• Consists of only one atom

• Can be positively or negatively charged

• - Non-metal + Non-metals

• - Share electrons for stability

• - Aim for a full outer shell with 8 electrons

• - Differences in compounds noted by:

  • Number of shared electrons

  • Polarity

  • Arrangement of atoms

• -Formed between a metal and nonmetal

• Involves the transfer of electrons from the metal to the non-metal

• Governed by the octet rule, where atoms seek to have a full outer shell of eight electrons to achieve stability

• Shares two electrons from each element

• Shares three electrons from each element

• Maximum bond possible

• Share one electron from each element

• Combination of a nonmetal with a metal or metalloid

• Involves an unequal sharing of valence electrons between the nonmetal and metal/metalloid atoms

• Combination of two non-metal atoms

• Characterized by an equal sharing of valence electrons between the nonmetal atoms

• Results in a symmetrical molecular structure with balanced arrangements on both sides

• Results in an asymmetrical molecular structure lacking mirrored symmetry

• Unequal sharing creates partial negative and positive charges, leading to the formation of a dipole moment

• Defined as the tendency of an atom in a molecule to attract the shared pair of electrons towards itself

Electronegativity at 0.0 - 0.39

Electronegativity at 1.70 above

Electronegativity at 0.40 - 1.69

Sharing of Electrons - unequal

Sharing of Electrons - equal

Sharing of Electrons - transferred

• Predicts the arrangement of valence electrons and geometry of molecules

• unbonded electrons

• Electrons involved in chemical bonds

What does LEDS stand for?

Intermolecular Forces are the attractive forces between molecules. These forces play a crucial role in determining the physical properties of substances, such as boiling point, melting point, and solubility,

• The hydrogen atom has a partial negative charge, which allows it to form a strong electrostatic attraction with the lone pair of electrons on the electronegative atom in a neighboring molecule

• These forces occur between polar molecules and arise due to the attraction between the positive and negative ends (poles) of neighboring molecules

• These interactions occur between an ion and a polar molecule.

• The charged ion induces a dipole in the polar molecule, leading to an attractive force between them

• These are the weakest intermolecular forces and occur between all molecules

• They result from the temporary dipoles that arise due to the uneven distribution of electrons in molecules.

• Is a special type of dipole-dipole interaction

• Occurs when a hydrogen atom is bonded to a highly electronegative atom (such as nitrogen, oxygen, or fluorine).

Involves Permanent Dipoles exclusive to F, O, and N

Occurs between Polar Molecules

Strength of Attraction: Medium to high

Involves Temporary Dipoles

Occurs between Nonpolar Molecules

Strength of Attraction: Low

Involves Full Ion and Dipole

Occurs between Ion and Polar Molecules

Strength of Attraction: High

Involves Permanent Dipoles

Occurs between Polar Molecules

Strength of Attraction: Mediun

• The stronger the interactions between particles, the more solid they will be at room temperature

• It is related to the each in which the molecules move to pass to each other

• attraction between like and different molecules

• Temperature at which matter changes from solid to liquid form

• Temperature at which matter changes from liquid to gas

• The ability of a liquid to flow up a thin tube against the influence of gravity

• Adhesive forces pull the surface liquid up the side of the tube

• Cohesive forces pull the interior liquid with it

• have non-uniform and uniform intermolecular forces

• Results from the the inward attraction experienced by the molecules on a surface liquid

• It is the ability of a solute to dissolve in solvent “like dissolves like”

• States that in a given compound, the elemental components are in a fixed ratio

• This means that the elements that make up a compound are always going to be in the same mass ratio. If the ratio changes, then the compound is considered and entirely different compound

• No atoms can be created or destroyed in a chemical reaction, so the number of atoms that are present in the reactants has to balance the number of atoms that are present in the products. 

• A. Biomolecules are large in size which makes them macromolecules

  • B. Macromolecules are needed to broken down first before it can be absorbed by the body

• synthesis of two monosaccharides through the elimination of water

• addition of water to break down a disaccharide into smaller components

• Glycosidic bonds

• Double sugars

• Two 6 Carbon chains or rings

• Complex

• Used for storage and structure

• Starch, cellulose, and glycogen

• Simple sugar

• (CH2O)n

• Hydroxyl (OH) groups

• Carbonyl group (C=O)

• glucose + glucose

•  glucose + fructose

•  galactose + glucose

• Hydrophobic and nonpolar

• Phosphate groups are bonded by phosphodiester bonds

• Hydrophobic and nonpolar

• Structure: 

  • DNA - mainly found in nucleus (A, G, C, T). Controls transmission of hereditary effects. Double stranded (helix)

  • RNA - mainly found in the cytoplasm (A,G, C, U). single stranded.

• Made up of Carbon, Hydrogen, and Oxygen

• Most abundant macromolecules

• Known as amino acids (bonded by peptide bonds)

• Nucleotides - building blocks

• DNA - deoxyribonucleic acid (heredity)

• RNA - ribonucleic acid (protein production)

• Functions: 

  • Energy source

  • Generates heat which helps insulate the body while also protects the organs of the body

  • Gives structure to cell membranes

• Functions: 

  • Responsible for the transmission of inherent characters from parent to offspring

  • They are responsible for the synthesis of protein in our body

  • DNA fingerprinting is a method used by forensic experts to determine paternity and identification of criminals

  • Plays a significant role in biological evolution and genetics

• Functions: 

  • Stores and provides quick energy for the body to use

  • Helps with lowering blood cholesterol through dietary fibers

• Functions: 

  • Enzyme catalysts - specific for only one reaction

  • Defense - antibody protein which protects us from diseases

  • Transport and Support - hemoglobin, keratin, fibrin, collagen

  • Motion - actin and myosin

  • Regulation - some hormones, regulatory proteins on DNA, cell receptors

  • Storage of iron and calcium

•  specific for only one reaction

• hemoglobin, keratin, fibrin, collagen

• antibody protein which protects us from diseases

• some hormones, regulatory proteins on DNA, cell receptors

• actin and myosin

• Uses chemical symbols to show what happens during a chemical reaction showing

  • The substances that react

  • The substances formed

• breaking down of a single substance to produce two or more simpler substances

• One reactant is exchanged for one ion of a second reactant

• In general, a metal can displace any metal lower in the activity series.

• The same rule applies to halogens

• Synthesis reaction

• To combine to form a new compound

• Metathesis/ double composition

• Ions of 2 compounds exchange places in an aqueous solution, forming two new compounds

• Products: a precipitate and a soluble compound

• Complete

• Hydrocarbons + Oxygen = Carbon Dioxide and Water

• Incomplete

• Hydrocarbons + Oxygen = Carbon Monoxide, Carbon, and Water

• Involves using relationships between reactants  and/or products in a chemical reaction to determine desired quantitative data

• Means the measure of elements

• Average mass of the naturally occurring mixture of isotopes.

• Mass of the atom in atomic mass units (amu)

• Amount of a substance that contains as many elementary entities (atoms, molecules, or other particles) as there are atoms in exactly 12g (or 0.012 kg) of the carbon -12 isotope

• One atomic mass unit is defined as mass exactly equal to one-twelfth the mass of one carbon -12 atom

• 1 amu = 1661 x 10-24 g

• Actual number of atoms in 12g of carbon - 12 is determined experimentally: 

• Converting atoms → moles/moles → atoms

• Stoichiometric coefficients in a chemical equation

• Number of moles of each substance

  Number of moles that can be produced/is consumed

• Reactant used up first in a reaction

• The maximum amount of product formed depends on how much of this reactant was initially present

• Atomic mass but in grams per mole

• Mass (in grams or kilograms) of 1 mole of units (such as atoms or molecules) of a substance

• Unit: g/mol

• Reactants present in quantities greater than necessary to react with the quantities of the limiting reagent

ATOMIC MASS AND PERIODIC LAW ○ Father of the Periodic Table

LAW OF TRIADS

ATOMIC NUMBER AND MODERN PERIODIC LAW

LAW OF OCTAVES

arranged the elements according to atomic mass

Divided the table into three groups. ○ Grouped the elements with similar chemical properties into clusters of three

Modern Periodic Table were arranged by atomic number

Every eight elements has similar properties when the elements are arranged in the increasing order of the atomic masses.

○ A cycle

Measure of how much an attracts electron pairs in a chemical bond

Measure of an atom’s energy changes when an electron is added to a gaseous atom

Minimum energy required to remove an electron from a neutral atom when the molecule is in the gaseous state

Distance of the outermost or valence

Tells the size of an atom

COMBUSTION

combustion was a process in which phlogiston was released from the flammable substances.

LAW OF DEFINITE PROPORTION

states that a given chemical compound always contains the same elements in the exact same proportions by mass.

LAW OF MULTIPLE PROPORTION

states that when two elements combine to form more than one compound, the weights of one element that combine with a fixed weight of the other are in 9 a ratio of small whole numbers

ELEMENTS

an element was based on the observation that many substances can be decomposed into simpler substances

LAW OF CONSERVATION MASS ○ states that in a chemical reaction mass is neither created nor destroyed

was a process in which phlogiston was released from the flammable substances

states that when two elements combine to form more than one compound, the weights of one element that combine with a fixed weight of the other are in 9 a ratio of small whole numbers.

states that in a chemical reaction mass is neither created nor destroyed

an element was based on the observation that many substances can be decomposed into simpler substances

states that a given chemical compound always contains the same elements in the exact same proportions by mass

is a baby star

higher velocity of atoms results in high temperature

atoms become more tightly packed that lead to higher density and frequency of collisions between atoms and the mass of H and He become more spherical (higher H and He)

Triple-alpha process ○ He to C ○ ⁴⁄₂ a + ⁴⁄₂ a + ⁴⁄₂ a = ¹²⁄₆ C

Alpha ladder ○ C to Fe ○ ¹²⁄₆ C + ⁴⁄₂ a = ¹⁶⁄₈ O ○ Keep adding the alpha until Iron is reached

is a clump of gas, dust and particles that forms whenever circulated ● Uneven distribution of H and He allowed gravity to act in the areas if higher concentration to initiate the clumping of matter

red giant exhausted the nuclear fuel of elements

• that leads to an explosion of the star or a supernova

• the energy in the explosion will be converted to isotopes (to avoid the waste of energy)

Proton-proton chain reaction ○ ¹⁄₁H + ¹⁄₁ₕ = ²⁄₂ He

CNO Cycle ○ ¹²⁄₆ C + ¹⁄₁H = ¹³⁄₇ N + ¹⁄₁H = ¹⁴⁄₈ O

region in space where the pulling force of gravity is so strong that light is not able to escape

can take place at the end of a star's life and some are result of dying stars

Proton-proton chain reaction ○ ¹⁄₁H + ¹⁄₁ₕ = ²⁄₂ He

CNO Cycle ○ ¹²⁄₆ C + ¹⁄₁H = ¹³⁄₇ N + ¹⁄₁H = ¹⁴⁄₈ O

Indicators of a Chemical Reaction

– the amount of substance present

A catalyst speeds up a chemical reaction, without being consumed by the reaction. o It increases the reaction rate by lowering the activation energy

the measure of how much exposed area a solid object has, expressed in square units

defines to be the amount of force exerted per area

more particles to collide means more collisions; greater chance of successful collisions results in more product made in same time

particles are spread out, fewer collisions in a given volume; fewer successful collisions results in less product made in same time

particles are forced closer together, greater chance of collisions in given volume; more successful collisions results in more product made in same time

fewer particles to collide means less collisions; fewer successful collisions results in less product made in same time

The higher the temperature, the higher the reaction

In Greek, stokhein means element and matron means measure