Atomic Theory Flashcards
Define Atom
an atom is the smallest part of an element
Define Atomic Theory
the study of the nature of atoms and how they combine to form matter
What are the Basic Forms of Matter?
fire, water, earth, and air
What is Daltons Atomic Theory?
- all matter is made up of atoms
- all atoms of the same element have the same properties
- atoms of diff elements have different properties
- atoms of different elements can combine in specific ways to form new substances
- created the billard ball model
What is Thomsons Model?
the plum pudding model
What did Rutherford Experiment With?
- he shot a positively charged particles at a price of gold foil
- he predicted the particles would pass right through
- 1 in 1000 particles bounced back
What are the Bohr Energy Shells?
1st - 2 electrons
2nd - 8 electrons
3rd - 8 electrons
(outer shell = valence electrons)
Define Atomic Number
the number of protons in an atom
(also indicates number of electrons)
Define Atomic Mass (Top Right)
the avg mass of an elements atoms
Lewis Dot Diagram =
column number
What are the Properties of a Metal?
- solid and shiny
- good conductors of heat and electricity
- malleable and ductile
What are the Properties of a Metalloid?
- has properties of both metals and non metals
- conducts electricity but not well (semiconductors)
What are the Properties of a Non Metal?
- usually a liquid or gas
- poor conductors of heat and electricity
- good insulators
- not malleable (tend to break when bent = brittle)
Define the Octet Rule
atoms gain and lose electrons to become more stable
Define Ions
- an ionic charge is the charge an atom has when it loses or gains electrons
- an atom that has gained or lost electrons is called an ion
ex: Fe2+ = loses 2 electrons
Fe3- = gains 3 electrons
Define Cation
when an atom loses electrons and becomes positive
Define Anion
when an atom gains electrons and becomes negative
Define Isotope
a neutral atom that has the same number of protons and electrons (change in mass)
Define Ionic Isotope
an atom that has a charge and a change in mass
What does the Periods on a Periodic Table Represent?
the number of energy levels
What does the Column Number on a Periodic Table Represent?
the number of valence electrons
Group 1A is?
- alkali or active metals
- soft, silver/grey metals
- malleable, ductile
- conduct heat and electricity
Group 2A is?
- alkaline earth metals
- react with water (weaker than group 1A)
Group 7A is?
- halogens
- colourful non metals
- gasses or with slight heating become gasses
- reactive and very poisonous
- used as disinfectants
Group 8A is?
- noble or inert gases
- exist naturally as colourless gasses
- glows when an electric current is passed through (neon lights)
- do not react
Define Compound
a compound is made up of two or more elements that are chemically combined
What are the Properties of an Ionic Compound?
- consists of a metal and a non metal
- electrons are transferred from 1 atom to another
- have high melting points
- dissolves in water to form a solution that conducts electricity
- solids at room temp
- formed when ions transfer electrons
- pos and neg ions attract and form an iconic bond
How is an Ionic Compound Formed?
- electrons are transferred from a metal to a non metal
- the metal becomes + and the non metal becomes -
- electrons fill open spots to fulfill the octet rule and create stability
Ca1F2
calcium fluoride
Aluminum Oxide
Al2O3
Define Multi Valent Iconic Compounds
- elements with multiple valences are indicated in the periodic table
- name using a roman numeral to indicate the charge if there is more than one
Lead (ll) Nitride
Pb3N2
PbO2
Lead (IV) Oxide
Define Polyatomic Ionic Compounds
a polyatomic ion is a charge group of atoms bonded together, also known as radical
Na(ClO3)
sodium chlorate
Aluminum Sulfate
Al2(SO4)3
Ca(OH)2
calcium hydroxide
Lithium and Phosphate
Li3(PO4)
Define Molecular Compunds
- when 2 or more non metals combine
- electrons are shared between atoms in a covalent bond
- can be solids, liquids, or gases
- good insulators and poor conductors of electricity
- low boiling points
How is a Molecular Compound Formed?
- unpaired electrons are shared between non metals using a loop or line to represent the bond of 2 shared electrons
- unpaired electrons are shared between atoms to create covalent bonds
Naming and Formulas of Molecular Compounds
1 = mono
2 = di
3 = tri
4 = tetra
5 = pentra
N2O3
dinitrogen trioxide
carbon tetraflouride
CF4
Cl2
chlorine gas
