ELS (2nd sem)

Nuclear Decay

The spontaneous change of an unstable atomic nucleus into a more stable one by emitting particles or energy.

Alpha Decay

Radioactive decay in which an atomic nucleus emits helium nucleus

Beta Decay

Type of radioactive nuclear decay in which an unstable nucleus becomes more stable by emitting a beta particle.

Gamma Decay

A radioactive decay which make the atom emit an electromagnetic wave “Gamma Radiation”

James Chadwick

Discovered neutron

J.J Thomson

• Discovered Electron

• Proposed the Plum pudding model

John Dalton

• First modern atomic theory

• Proposed the Solid sphere model

Nucleosynthesis

Process of creating new atomic nuclei.

Nuclear Fusion

Reaction in which two light atomic nuclei combine

Nuclear Fission

Reaction in which a heavy atomic nucleus splits into two

Isotope

An element that have the same number of protons but different in number of neutrons.

Ionic Bond

• Transfer of electrons

• Between metal and non-metal

• Example: NaCl

Covalent Bond

• Sharing of electrons

• Between non-metals

Polar

Unequal sharing (H₂O)

Non-polar

Equal sharing (O₂)

Electronegativity

The ability of an atom to attract electrons toward itself when forming a chemical bond.

Large difference

ionic bond = Greater than 1.7

Small difference

NonPolar covalent = Less than 0.5

Unequal sharing

Polar covalent bond 0.5 – 1.7

Intermolecular Force (IMF)

A force of attraction between molecule

London Dispersion Forces

Caused by the movement of electron

• Weakest force

• Caused by temporary dipoles

• Present in all molecules

Dipole–Dipole Forces

Polar molecules

• Between polar molecules

• Attraction between positive and negative ends

Hydrogen Bonding

A polar molecule with hydrogen bonded with F,O,N

Ion Dipole

An attractive force between a charged ion (cation or anion) and a polar molecule (dipole).

Biomolecules

molecules produced by living organisms that are essential for life.

Carbohydrates

Energy source

Monosaccharides

Simple sugar (Glucose)

Disaccharides

2 sugars (Sucrose)

Polysaccharides

Complex Sugar (Starch, Cellulose)

Proteins

• Amino acid

• Function: Build & repair tissues, enzymes

• Examples: Collagen, Hemoglobin

Lipids

• Function: Energy storage, insulation, cell membrane

• Examples: Triglycerides, Phospholipids, Steroids

Nucleic Acids

• Nucleotides

• Function: Store & transmit genetic information

• Examples: DNA, RNA

Collision Theory

chemical reactions occur when reactant particles collide with:

• Sufficient energy (activation energy, Ea)

• Proper orientation

Concentration

more particles → more collisions

Temperature

higher temp → faster particles → more collisions

Surface area

more exposed area → more collisions

Catalyst

lowers activation energy, increases reaction rate

Active ingredients

Ingredients that component of a product that performs the main function.

Ethanol

Hand sanitizer

Fluoride

Toothpaste

Surfactant

Detergent

Inactive ingredients

Ingredients are the components of a product that do not perform the main function, but help with stability preservation, appearance and fragrance