Chem Quiz #1 Flashcards
What is the Atomic Theory?
Atomic theory is the scientific theory that matter is composed of particles called atoms
Dalton’s Atomic Theory
- all matter is composed of tiny, individual particles called atoms
- atoms of an elemnet have identical properties
- atoms of different elements have different properties
- atoms of two or more elements can combine in constant ration to form a new substance
J.J. Thompson’s Atomic Theory
Raisin Bun
- discovery of electrons
- raisun bun or plum pudding model
- atom is sphere which is positive, with negative electrons embedded in it like raisins in a bun
- most of the mass is associated with the psotive charge
Ernest Rutherford’s Atomic Theory
Nucleus
- atoms have a nucleus which is positive and has most of the mass
- most of the atom is empty space, occupied by the moving negatively charged atoms
- propsed the existence of protons
Neils Bohr’s Atomic Theory
Planetary Model
- electrons move in circular orbits around the nucleus
- cannot exist between orbits
James Chadwick’s Atomic Theory
Neutrons
- showed that the nucleus mus contain heavy neutral particle to account for all of the atom’s mass (neutrons)
Schrodinger/de Broglie’s Atomic Theory
Quantum Model
- Quantum Mechanical model
- electrons have distinct energy levels
- exact location of electrons are not defined, but the probable reaction in a region of space can be predicted
What is a Proton?
- positive charge subatomic particle
- found in nucleus
- determines the type of element
What is a Neutron?
- neutral charge subatomic particle
- found in nucleus
- used to hold nucleus together
What is an Electron?
- smallest subatomic particle
- negative charge
- found in “cloud” region
- arranged in energy levels
What is Atomic Mass?
- AMU is the mass of a proton or neutron = 1.7 x 10 to the power of -24g
- net charge for all atoms is 0
- e- = #p+ in a neutral atom
- mass number is the sum of protons and neutrons (rounded to nearest whole number)
- used to find the number neutrons
What is an Isotope?
- atoms that have same number of protons but a different number of neutrons
- atomic mass on the periodic table is an average mass based on the % abundances of all naturally occuring isotopes of the element
- provide atomic mass in the name
The Periodic Table
- Metals
- Non Metals
- Metalloids along stair case
What is the Atomic Number?
- number of protons in one atom of an element
- increases from left to right and top to bottom
What are the properties of Metals?
- good conductors
- strong
- malleable
- ductile
- high lustre
- are found on left side of staircase
What are the properties of Non-Metals?
- poor conductors
- non lustrous
- weak
- non ductile
- non malleable
- opposite properties of metals
- found on right side of staircase
What are the properties of Metalloids?
- shows properties of both metals and non metals
- found along the stair case
How many groups are there in the Periodic Table?
- 18 vertical groups called families
- labelling system: Roman Numeral and letters or ordinary numbers
What is Group 1 (IA)?
Alkali Metals (very reactive)
What is Group 2 (IIA)?
Alkaline Earth Metals (less reactive)
What is Group 17 (VIIA)?
Halogens (reactive non metals)
What is Group 18 (VIIIA)?
Inert or Noble Gases (unreactive)
What is the Lanthanide Series (IA)?
Rare Earth (57-71)
What is Group 3-12 (B Series)
Transition Metals
Elements in each group share _______?
Similar chemical properties although intensity changes
Reactivity _______ for Metals and _______ for Non Metals
Down group for Metals and Up Group for Non Metals
The Group Number indicates ____?
How many electrons are in the outer most energy level
What are Periods?
- horizantal rows
- show a trend in reactivity which changes left to right
- each time you move to a new period you start the trend over
What is an EELD?
Energy Electon Level Diagram
Level 4 - max 8e-
Level 3 - max 8e-
Level 2 - max 8e-
Level 1 - max 2e-
- energy levels- shows number of e- in each level (# of levels = period)
What are Ions?
Ions are atoms or groups that have a net charge
- number of protons and electrons are not equal
- most atoms try to achieve the electron configuration of a nobel gas
What does Isoelectronic mean?
means having the same number of electrons as another atom or ion
eg) fluorine gains an electron to be isoelectronic with neon
What are Cations?
- Positively charged ions
- lost electrons to obtain a stable electron configuration (full valence level)
- charge on a metal ion is the same as the group number for groups 1,2,3,13,14
- metals form Cations
What are Anions?
- negatively charged ions
- gained electrons to obtain a stable electron configuration (full valence level)
- charge on a non-metal is 18-group #
How do you write a EELD for atoms?
P+
E-
N
Level 4 - 2e-
Level 3 - 8e-
Level 2 - 8e-
Level 1 - 2e-
Nucleus (Proton and Neutrons)
Element Symbol
How do you write a EELD for ions?
Level 4 - 2e- (charge on top)
Level 3 - 8e-
Level 2- 8e-
Level 1- 2e-
Nucleus (Proton and Neutron)
Element Symbol with Charge
*make sure to bracket all of the EELD
What is the EELD formula for Ions?
P = atomic number
E = # of protons - charge
N = atomic mass - atomic number
eg) sodium
P = 11
E = 11 - (+1) = 10
N = 12
Atoms have _______ and Ions have ________
- Atoms have same e- and p+, no charge
- Ions have either negative or positive charge
Metallic elements exist as _____
Single atoms, monatomic
Chemical is the _____ followed by the ______ at room temperature
Symbol, State
Non Metals do not exist as _______ and are called _______
Single Atoms, Molecular Elements
Molecular compounds are formed when?
2 or more non metals bond together
Molecular compounds are bonded by?
Covalent bonds which is the force of attraction between atoms that are sharing electrons
Properties of Molecular Compounds
- Do not conduct electricity when dissolved in water
- dissolve in water to form a neutral molecular solution or an acidic solution
- solid, liquid or gas at room temperature
How do you name Molecular Compounds?
- give the atom name for the first element (with prefix if there is more than one)
- give the name for the second element, add ide ending and include prefix
*if first element is hydrogen, no prefix it is an acid
eg) CO(g) Carbon Monoxide
What are the prefixes?
1 - Mono
2 - Di
3 - Tri
4 - Tetra
5 - Penta
6 - Hexa
7 - Septa
8 - Octa
9 - Nona
10 - Deca
How do you write Molecular Formulas?
Write each symbol followed by the subscript (from prefix)
What is Ammonia?
NH3
What is Water?
H2O
What is Methane?
CH4
What is Methanol?
CH3OH
What is Ethane?
C2H6
What is Ethanol?
C2H5OH
What is Glucose?
C6H12O6
What is Sucrose?
C12H22O11
What is Ozone?
O3
What is Hydrogen Peroxide
H2O2
