review unit. investigation report outline purpose most often to create, test or use a chemistry...
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Investigation Report Outline
Purpose
Most often to create, test or use a chemistry concept.
Problem
A specific question to be answered in terms of the manipulated and responding variables.
Hypothesis and/or Prediction
A predicted answer to the problem, including reasoning.
(pgs. 790 – 794)
Investigation Report OutlineMaterials
Complete list of all equipment and chemicals.
Procedure
Detailed set of numbered steps to answer the Problem.
Evidence
All quantitative and qualitative observations relevant to answering the Problem. Use tables whenever possible.
Investigation Report Outline
Analysis
Manipulations, interpretations and calculations based on the evidence. It concludes with a statement that answers the Problem.
Evaluation
1. Evaluation of the Investigation
2. Evaluation of the Prediction
3. Revisiting the Purpose
pgs. 4 & 5 Are You Ready #’s 1, 2, 4, 5, 9, 10, 11
Pg. 6 Starting Points #’s 1 – 5
Read pgs. 790 - 794
Read pgs. 6 – 11 pg. 11 Section 1.1 Questions #’s 1 – 8
Semi-metals (or metalloids) are all of the elements that border the staircase line except aluminium.
Read pgs. 12 – 13
pg. 13 Section 1.2 Questions #’s 1 – 5
Read pgs. 14 – 16
pg. 16 Section 1.3 Questions #’s 1 – 8
John Dalton(1766 - 1844)
The “billiard ball” model
Dalton’s Atomic Theory
Matter is composed of indestructible, indivisible atoms which are identical for one element, but different from other elements.
J.J. Thomson(1856 – 1940)
The “raisin bun” model
An atom consists of one large positive charge and many small negative charges embedded in it.
Thomson’s Atomic Model
"Could anything at first sight seem more impractical than a body which is so small that its mass is an insignificant fraction of the mass of an atom of hydrogen? --which itself is so small that a crowd of these atoms equal in number to the population of the whole world would be too small to have been detected by any means then known to science."
- an excerpt from a speech he made in 1934J.J. Thomson(1856 – 1940)
Ernest Rutherford(1871 –
1937)
The “planetary” or “nuclear” model
Every atom has a tiny, extremely dense positive core which he called the nucleus.
The negative electrons orbit the nucleus like planets around the sun.
Rutherford’s Atomic Theory
Rutherford was surprised when all the particles did not go straight through the gold foil. He realized that each atom must have a dense core of positive charge.
The mass number of an atom is equal to the number of particles in the nucleus (protons and neutrons).
The atomic number of an atom is equal to the number of protons in the nucleus.
Three naturally occurring isotopes of carbon:
126 C 13
6 C 146 C
The bottom number is sometimes not written because you can determine the atomic number from the symbol.
Any sample of an element found in nature is a mixture of different isotopes. Each isotope will occur in different proportions, usually given as a percentage.
For example:Each of these isotopes contains 50 protons.
Neils Bohr(1885 –
1962)
Electrons are arranged around the nucleus in very specific orbits or energy levels.
Bohr’s Atomic Theory
The period number (horizontal row) that an element is in is the
same as the number of energy levels the atom has.
Level Max. # of Electrons
1 2
2 8
3 8
4 18
All the elements in a group have the same electron configuration in their outermost shells. Electrons in the outer shell that is not full are called valence electrons.
When an electron absorbs energy, it jumps to a higher energy level.
When an electron transitions back to a lower level, energy is given off.
The light given off by the different possible transitions is called a line spectrum.
Bohr used the light emitted from excited hydrogen atoms to form his ideas about the structure of the atom.
The hydrogen emission spectrum
An ion is a an atom (or a group of atoms) that has a positive or negative electric charge.
Recall that an atom of any element is neutral, so the number of protons equals the number of electrons.
The formation of an ion is called ionization, and is the result of an atom either gaining or losing electrons.
The number of protons only changes in nuclear reactions,
never in the formation of ions.
Cations are positively charged ions.
Ant-ion?
Anions are negatively charged ions.
They are formed when a metal atom loses valence electrons (electrons in the outermost energy level).
They are formed when a non-metal atom accepts electrons into its outer energy level.
Empirical Classification of Ionic and Molecular Compounds
Recall that empirical knowledge is observable.
Names and Formulas of Ionic Compounds
Binary Compounds
aluminum fluoride
silver sulfide
potassium iodide
3 sAlF
2 sAg S
sKI
sMgO
3 2 sCa P
2 sBaBr
You must ALWAYS include the state of matter when writing an empirical formula.
magnesium oxide
calcium phosphide
barium bromide
Names and Formulas of Ionic Compounds
Multi-Valent Metals
iron (III) chloride
lead (IV) oxide
nickel (III) sulfide
3 sFeCl
2 sPbO
2 3 sNi S
2 sFeCl
sCrN
2 sCu O
If the ion of a multivalent metal is not specified, you can assume the charge on the ion is the most common one.
iron (II) chloride
chromium (III) nitride
copper (I) oxide
Names and Formulas of Ionic Compounds
Compounds with Polyatomic Ions
barium hydroxide
iron (III) carbonate
copper (I) permanganate
gold (III) nitrate
ammonium phosphate
potassium dichromate
3 3 (s)Au NO
4 4 (s)3NH PO
2 2 7 (s)K Cr O
2 (s)
Ba OH
2 3 3 (s)Fe CO
4 (s)CuMnO
The polyatomic ion must be in brackets only when there is more than one.
Ionic Hydrates
An ionic hydrate is an ionic compound that has loosely-bonded water molecules.
4 2 (s)CuSO 5H Ocopper (II) sulfate pentahydrate
copper (II) sulfate-5-water
copper (II) sulfate-water (1/5)
water ( H2O(l) )
ammonia ( NH3 (g) ) methane ( CH4 (g) )
A molecule is a group of nonmetal atoms held together by covalent bonds.
A molecular formula indicates the number of atoms of each type.
“I Bring Clay For Our New House.”
2 (g) 2 (l) 2 (g) 2 (g) 2 (g) 2 (g) 2 (g)I Br Cl F O N H
4 (s) 8 (s)P S
“And four Paving stones for eight Steps.”
“And three Octopuses for pets!”
3 gO
In a covalent bond, electrons are shared between nonmetal atoms in pairs.
two chlorine atoms one chlorine molecule
a pair of shared electrons
2 gCl
water (H2O)
an oxygen atom and two hydrogen atoms
a water molecule
two pairs of shared electrons
In a covalent bond, electrons are shared between nonmetal atoms in pairs.
Name Formula
carbon dioxide
dinitrogen monoxide
phosphorus trichloride
oxygen difluoride
dinitrogen tetrasulfide
sulfur trioxide
2 (g)CO
2 (g)N O
3 (g)PCl
2 (g)OF
2 4 (g)N S
3 (g)SO
PrefixNumber
of Atoms
mono 1
di 2
tri 3
tetra 4
penta 5
hexa 6
septa 7
octa 8
nona 9
deca 10
Naming Binary Molecular Compounds
When there is one of the first element only, then the prefix mono is dropped.
Naming and Writing Formulas for Acids and Bases
Formula IUPAC Name Classical Name
aqueous hydrogen bromide
aqueous hydrogen chromate
aqueous hydrogen nitrite
aqueous hydrogen sulfate
aqueous hydrogen iodide
aqueous hydrogen sulfite
hydrobromic acid
chromic acid
nitrous acid
sulfuric acid
hydroiodic acid
sulfurous acid
(aq)HBr
2 4 (aq)H CrO
2 (aq)HNO
2 4 (aq)H SO
(aq)HI
2 3 (aq)H SO
To name acids, we use the three rules on the data booklet. Note that all acids are aqueous solutions.