Bell Work Prepare for Quiz Hey Kim…. Write these in your Bell Work Composition Book 1.Kr 2.Ar...
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Bell Work Prepare for Quiz Hey Kim….
Bell Work Prepare for Quiz Hey Kim…. Write these in your Bell Work Composition Book 1.Kr 2.Ar 3.Neon 4.Hellium 5.Astatine 6.F 7.Chlorine 8.Bromine 9.Iodine
Write these in your Bell Work Composition Book 1.Kr 2.Ar 3.Neon
4.Hellium 5.Astatine 6.F 7.Chlorine 8.Bromine 9.Iodine 10.Xenon
11.Rn 12.Mn 13.Iron 14.Co 15.Nickel 16.Cu 17.Zinc 18.Ag 19.Au
20.Hg
Slide 4
Answers: 7A, 8A and transition elements 1.Kr - Krypton 2.Ar -
Argon 3.Neon - Ne 4.Helium - He 5.Astatine - At 6.F - Fluorine
7.Chlorine - Cl 8.Bromine - Br 9.Iodine - I 10.Xenon - Xe 11.Rn -
Radon 12.Mn - Manganese 13.Iron - Fe 14.Co - Cobalt 15.Nickel - Ni
16.Cu - Copper 17.Zinc - Zn 18.Ag - Silver 19.Au - Gold 20.Hg -
Mercury
Slide 5
Todays Element Zn Zinc Zn Periodic Table Placement Group 2B or
12 Period 4 Video: Is Zinc Boring?
Slide 6
Zinc Chemical PropertiesPhysical Properties Importance Periodic
Table Atomic # Atomic mass # of Protons # of Electrons # of
Neutrons Period Group
Slide 7
Whats in a Battery?Battery Modern batteries use a variety of
chemicals to power their reactions. Common battery chemistries
include: Zinc-carbon battery: The zinc-carbon chemistry is common
in many inexpensive AAA, AA, C and D dry cell batteries. The anode
is zinc, the cathode is manganese dioxide, and the electrolyte is
ammonium chloride or zinc chloride.zinc Alkaline battery: This
chemistry is also common in AA, C and D dry cell batteries. The
cathode is composed of a manganese dioxide mixture, while the anode
is a zinc powder. It gets its name from the potassium hydroxide
electrolyte, which is an alkaline substance. Lithium-ion battery
(rechargeable): Lithium chemistry is often used in high-
performance devices, such as cell phones, digital cameras and even
electric cars. A variety of substances are used in lithium
batteries, but a common combination is a lithium cobalt oxide
cathode and a carbon anode. Lead-acid battery (rechargeable): This
is the chemistry used in a typical car battery. The electrodes are
usually made of lead dioxide and metallic lead, while the
electrolyte is a sulfuric acid solution.
Slide 8
Water: Separation by Electrolysis Video of Electrolysis: Water
to Hydrogen and Oxygen
Slide 9
Slide 10
Atomic Mass of a Compound H 2 O Try these CO 2 C 6 H 12 O 6
1.01 + 1.01 + 16 = 18.02 H 2 1.01 x 2 = 2.02 O 16 x 1 = 16.00 Add
totals 2.02 + 16.00 18.02
Slide 11
Practice Finding Atomic Mass CO 2 C 12.01 x 1 = 12.01 O 2 16 x
2 = 32.00 Add totals 12.01 + 32.00 44.01
Slide 12
Practice Finding Atomic Mass C 6 H 12 O 6 C 6 12.01 x 6 = 72.06
H 12 1.01 x 12 = 12.12 O 2 16 x 6 = 96.00 Add totals 72.06 12.12
+96.00 108.18
Slide 13
Percent Composition of Mass for Mixtures A 6g mixture of sulfur
and iron is separated using a magnet. Data Sulfur (S) Iron (Fe) 5g
1g Calculate the percent composition of S and Fe.
Slide 14
Percent Composition of Mass for Mixtures A 6g mixture of sulfur
and iron is separated using a magnet. Data Sulfur (S) Iron (Fe) 5g
1g Calculate the percent composition of S and Fe. Part / Whole x
100 = % composition Sulfur: 5g/6g x 100 = Iron : 1g/6g x 100 =
Slide 15
Percent Composition of Mass for Mixtures A 6g mixture of sulfur
and iron is separated using a magnet. Data Sulfur (S) Iron (Fe) 5g
1g Calculate the percent composition of S and Fe. Part / Whole x
100 = % composition Sulfur: 5g/6g x 100 = 83.33% S Iron : 1g/6g x
100 = 16.66% Fe
Slide 16
Use Percent Composition to find the composition of a compound
Use the periodic table to find the compounds percent composition of
each element. List the atomic weight of each element in the
compound Note how many of each type of atom is in the compound Add
it all up to get the atomic weight of the whole compound
Slide 17
Atomic Mass of a Compound H 2 O Try these CO 2 C 6 H 12 O 6
1.01 + 1.01 + 16 = 18.02 H 2 1.01 x 2 = 2.02 O 16 x 1 = 16.00 Add
totals 2.02 + 16.00 18.02
Slide 18
Practice Percent Composition H 2 O part / whole x 100 = %
composition % composition of H % composition of O
Slide 19
Practice Percent Composition CO 2 part / whole x 100 = %
composition % composition of C % composition of O
Slide 20
Practice Percent Composition C 6 H 12 O 6 part / whole x 100 =
% composition % composition of C % composition of H % composition
of O
Slide 21
Law of Conservation of Mass Mass is neither created nor
destroyed in any process. It is conserved. Mass reactants = Mass
products 2H 2 O + electricity yields 2H 2 + O 2
Slide 22
Isotopes The atomic weight found on the periodic table is based
on the average weight of all the isotopes of the element Isotope
atoms of the same element with the same number of protons but
different numbers of neutrons M&M activity
Slide 23
Writing Isotopes
Slide 24
Reading Isotopes Mass number - the sum of the protons and
neutrons
Steps in the Scientific Method 1.Observations 1.Observations -
quantitative - quantitative - qualitative - qualitative
2.Formulating hypotheses 2.Formulating hypotheses - possible
explanation for the observation - possible explanation for the
observation 3.Performing experiments 3.Performing experiments -
gathering new information to decide - gathering new information to
decide whether the hypothesis is valid whether the hypothesis is
valid
Slide 34
Outcomes Over the Long-Term Theory (Model) Theory (Model) - A
set of tested hypotheses that give an - A set of tested hypotheses
that give an overall explanation of some natural phenomenon.
overall explanation of some natural phenomenon. Natural Law Natural
Law - The same observation applies to many - The same observation
applies to many different systems different systems - Example - Law
of Conservation of Mass - Example - Law of Conservation of
Mass
Slide 35
Law vs. Theory A law summarizes what happens A law summarizes
what happens A theory (model) is an attempt to explain why it
happens.
Slide 36
Nature of Measurement Part 1 - number Part 1 - number Part 2 -
scale (unit) Part 2 - scale (unit) Examples: Examples: 20 grams 20
grams 6.63 x 10 -34 Joule seconds 6.63 x 10 -34 Joule seconds
Measurement - quantitative observation consisting of 2 parts
consisting of 2 parts
Slide 37
The Fundamental SI Units (le Systme International, SI)
International System of Units a system of measurement units agreed
on by scientists to aid in the comparison of results
worldwide.International System of Units
Uncertainty in Measurement A digit that must be estimated is
called uncertain. A measurement always has some degree of
uncertainty.
Slide 42
Why Is there Uncertainty? Measurements are performed with
instruments No instrument can read to an infinite number of decimal
places Which of these balances has the greatest uncertainty in
measurement?
Slide 43
Precision and Accuracy Accuracy refers to the agreement of a
particular value with the true value. Precision refers to the
degree of agreement among several measurements made in the same
manner. Precision refers to the degree of agreement among several
measurements made in the same manner. Neither accurate nor precise
Precise but not accurate Precise AND accurate
Slide 44
Types of Error Random Error (Indeterminate Error) - measurement
has an equal probability of being high or low. Systematic Error
(Determinate Error) - Occurs in the same direction each time (high
or low), often resulting from poor technique or incorrect
calibration. Systematic Error (Determinate Error) - Occurs in the
same direction each time (high or low), often resulting from poor
technique or incorrect calibration.
Slide 45
Rules for Counting Significant Figures - Details Nonzero
integers always count as significant figures. 3456 has 3456 has 4
sig figs. 4 sig figs.
Slide 46
Rules for Counting Significant Figures - Details Zeros Zeros -
Leading zeros do not count as - Leading zeros do not count as
significant figures. 0.0486 has 0.0486 has 3 sig figs. 3 sig
figs.
Slide 47
Rules for Counting Significant Figures - Details Zeros Zeros -
Captive zeros always count as - Captive zeros always count as
significant figures. 16.07 has 16.07 has 4 sig figs. 4 sig
figs.
Slide 48
Rules for Counting Significant Figures - Details Zeros Zeros
Trailing zeros are significant only if the number contains a
decimal point. Trailing zeros are significant only if the number
contains a decimal point. 9.300 has 9.300 has 4 sig figs. 4 sig
figs.
Slide 49
Rules for Counting Significant Figures - Details Exact numbers
have an infinite number of significant figures. 1 inch = 2.54 cm,
exactly 1 inch = 2.54 cm, exactly
Slide 50
Sig Fig Practice #1 How many significant figures in each of the
following? 1.0070 m 5 sig figs 17.10 kg 4 sig figs 100,890 L 5 sig
figs 3.29 x 10 3 s 3 sig figs 0.0054 cm 2 sig figs 3,200,000 2 sig
figs
Slide 51
Rules for Significant Figures in Mathematical Operations
Multiplication and Division: # sig figs in the result equals the
number in the least precise measurement used in the calculation.
6.38 x 2.0 = 6.38 x 2.0 = 12.76 13 (2 sig figs) 12.76 13 (2 sig
figs)
Slide 52
Sig Fig Practice #2 3.24 m x 7.0 m CalculationCalculator
says:Answer 22.68 m 2 23 m 2 100.0 g 23.7 cm 3 4.219409283 g/cm 3
4.22 g/cm 3 0.02 cm x 2.371 cm 0.04742 cm 2 0.05 cm 2 710 m 3.0 s
236.6666667 m/s240 m/s 1818.2 lb x 3.23 ft5872.786 lbft 5870 lbft
1.030 g 2.87 mL 2.9561 g/mL2.96 g/mL
Slide 53
Rules for Significant Figures in Mathematical Operations
Addition and Subtraction: The number of decimal places in the
result equals the number of decimal places in the least precise
measurement. 6.8 + 11.934 = 6.8 + 11.934 = 18.734 18.7 (3 sig figs)
18.734 18.7 (3 sig figs)
Slide 54
Sig Fig Practice #3 3.24 m + 7.0 m CalculationCalculator
says:Answer 10.24 m 10.2 m 100.0 g - 23.73 g 76.27 g 76.3 g 0.02 cm
+ 2.371 cm 2.391 cm 2.39 cm 713.1 L - 3.872 L 709.228 L709.2 L
1818.2 lb + 3.37 lb1821.57 lb 1821.6 lb 2.030 mL - 1.870 mL 0.16 mL
0.160 mL
Slide 55
In science, we deal with some very LARGE numbers: 1 mole =
602000000000000000000000 In science, we deal with some very SMALL
numbers: Mass of an electron = 0.000000000000000000000000000000091
kg Scientific Notation
Slide 56
Imagine the difficulty of calculating the mass of 1 mole of
electrons! 0.000000000000000000000000000000091 kg x
602000000000000000000000 x 602000000000000000000000
???????????????????????????????????
Slide 57
Scientific Notation: A method of representing very large or
very small numbers in the form: M x 10n M x 10n M is a number
between 1 and 10 n is an integer
Slide 58
2 500 000 000 Step #1: Insert an understood decimal point. Step
#2: Decide where the decimal must end up so that one number is to
its left up so that one number is to its left Step #3: Count how
many places you bounce the decimal point the decimal point 1234567
8 9 Step #4: Re-write in the form M x 10 n
Slide 59
2.5 x 10 9 The exponent is the number of places we moved the
decimal.
Slide 60
0.0000579 Step #2: Decide where the decimal must end up so that
one number is to its left up so that one number is to its left Step
#3: Count how many places you bounce the decimal point the decimal
point Step #4: Re-write in the form M x 10 n 12345
Slide 61
5.79 x 10 -5 The exponent is negative because the number we
started with was less than 1.
Slide 62
PERFORMING CALCULATIONS IN SCIENTIFIC NOTATION ADDITION AND
SUBTRACTION
Slide 63
Review: Scientific notation expresses a number in the form: M x
10 n 1 M 10 n is an integer
Slide 64
4 x 10 6 + 3 x 10 6 IF the exponents are the same, we simply
add or subtract the numbers in front and bring the exponent down
unchanged. 7 x 10 6
Slide 65
4 x 10 6 - 3 x 10 6 The same holds true for subtraction in
scientific notation. 1 x 10 6
Slide 66
4 x 10 6 + 3 x 10 5 If the exponents are NOT the same, we must
move a decimal to make them the same.
Slide 67
4.00 x 10 6 + 3.00 x 10 5 Student A 40.0 x 10 5 43.00 x 10 5 Is
this good scientific notation? NO! = 4.300 x 10 6 To avoid this
problem, move the decimal on the smaller number!
Slide 68
4.00 x 10 6 + 3.00 x 10 5 Student B.30 x 10 6 4.30 x 10 6 Is
this good scientific notation? YES!
Slide 69
A Problem for you 2.37 x 10 -6 + 3.48 x 10 -4
Slide 70
2.37 x 10 -6 + 3.48 x 10 -4 Solution 002.37 x 10 -6 0.0237 x 10
-4 3.5037 x 10 -4
Slide 71
Direct Proportions The quotient of two variables is a constant
As the value of one variable increases, the other must also
increase As the value of one variable decreases, the other must
also decrease The graph of a direct proportion is a straight
line
Slide 72
Inverse Proportions The product of two variables is a constant
As the value of one variable increases, the other must decrease As
the value of one variable decreases, the other must increase The
graph of an inverse proportion is a hyperbola