SALTS

A salt is a substance formed when hydrogen ions of an acid are partially or completely replaced by metal ions or ammonium ions

Solubility of Salts

Preparation of Salts

+ Acid + Metal Oxide        >  Salt + Water
+ Acid + Active Metals      >  Salt + Hydrogen Gas
+ Acid + Metal Carbonate >  Salt + Water + Carbon Dioxide

Preparation of Soluble Salts

+ Acid + Alkali > Salt + Water

Chemical Bonds

Ionic Compound

+ strong electrostatic attraction
+ high melting/boiling
+ conduct electricity in molten/aqueous state
+ not soluble in organic solvents
+ some soluble in water

Covalent Compound

+ strong intra-molecular bonds
+ weak intermolecular attraction
+ low boiling/melting
+ do not conduct electricity
+ not soluble in water
+ soluble in organic solvents

Periodic Table of Elements

Group 1

+ alkaline metals
+ low melting/boiling/densities
+ reactivity decreases down the group
+ react with halogen/oxygen/hydrogen/water
+ groups form ionic bonding

Transition Elements

+ form complex ions
+ different oxidation number
+ high melting/boiling/density
+ act as a catalyst

Group 17

+ known as halogens(diatomic)
+ all non-metals
+ reactivity decreases down the group
+ react with water/hydroxide/iron/phosphorus
+ oxidizing agents decreases down the group

Group 18 

+ monoatomic gases
+ unreactive(stable)
+ low melting/boiling/density
+ cannot conduct heat/electricity
+ insoluble in water

Isotopes

Definition

* Atom of the same element
> same proton number
> different nucleon/neutrons number

* Same chemical properties
* Different physical properties

Example of Isotopes/Radio Isotopes

Cobalt 60             kill cancerous cells
Gamma ray          destroy bacteria/infertile animal
Carbon 14           carbon dating(archeology)
Phosphorus 32     determine intake of fertilizer in plants
Sodium 24           detect pipe leakages/blood clot

Atomic Models

John Dalton

~small,invisible sphere, atom is the smallest

J.J Thompson

~discovered electron

Ernest Rutherford

~discovered proton

Neils Bohr

~discovered orbit

James Chadwick

~discovered neutron

Radioactivity

Radioactive decay

Definition

Unstable nucleus > stable nucleus + radiation/energy

~spontaneous decomposition/disintegration of unstable nucleus into stable nucleus by emitting radiation/energy/

   photons

Types of Radiation

Scarlet Fever

Scarlet fever is an infectious disease caused by bacteria known as group A Streptococcus (GAS). GAS causes many other infections, but the strain of GAS bacteria that causes scarlet fever is different because it produces a toxin. The toxin causes the characteristic red skin rash for which scarlet fever is known. Scarlet fever is more common in children (ages 4-8) than adults. The infection often starts in the throat and has the symptoms of a typical strep throat but goes on to produce the skin rash. Scarlet fever is usually mild and resolves with antibiotic treatment. However, a small proportion of people experience very severe disease that may include bacterial invasion into the bloodstream (sepsis), tissues, or bone. Severe disease was more common before the discovery of antibiotics

Signs and Symptoms
+ sore throat
+ fever
+ headache
+ enlarged lymph nodes in the neck
+ fatigue
+ abdominal pain and vomiting(normally children)
+ skin rash(after two days start from chest-trunk-arms-legs)


Treatment
+ oral penicillin/amoxicillin(taken normally 10 days)