Chem Final Sem 1 Flashcards
Creation Mandate: What is it where do you find it
What God wants us to do: Create products and solve problems, Weigh the consequences of actions, Seek a balance, Love neighbors
Scientific models: What are they? What are they used for
Simplifies something in the world to explain, describe, or represent
When was chemistry first taught as an academic discipline
1800
Biblical worldview
How someone sees and interprets life using Bible as guide
Quantitative data
Data with numbers, measurable
Qualitative data
Data without numbers, not measurable
Scientific method
Observation
Question
Hypothesis
Experiment
Data collection
Conclusion
Retest
DIfference between theory and hypothesis
Hypothesis: Suggested solution to problem, testable, written as if… then, predicts outcome
Theory: Principle formed to explain things already shown in data
Observation
What do you see happening
Data
Info/fact/stats collected for analysis
You set up an experiment to test the idea that the amount of nitrogen in the soil affects plant growth
What is your hypothesis
What would be the experimental and control group be
What is the dependent and independent variables
Hypothesis: If there is a lot of nitrogen, then plant growth improves
Experimental: Soil with a lot of nitrogen
Control: Normal soil
Dependent: Plant growth
Independent: Nitrogen, soil
Ex nihilo
Out of nothing
Density formula
Mass over volume
Physical property
We can measure without changing material into another substance
Chemical property
How matter acts when other materials are combined together
How material changes composition when enough energy is added to it
Conductivity
Ability of material to transfer heat or electricity between its particles
Ductility
Describes how easily materials can be drawn into thin wires
Malleability
How easily material can be hammered into shapes
Luster
based on whether the mineral is metallic or non-metallic
Physical change
Example: Spoiled milk or cut up paper
Change in physical properties
Substance remains same
Start with A end with A
Paper that is cut
Chemical change
Example: Spoiled milk or cut up paper
Substance changes
New substance formed
Composed of different particles
Start with A end with B
Spoiled milk
Mixtures: Heterogenous/homogenous/suspensions what are they
Hetero/suspension: Parts settle out bc gravity
Homo: Uniform mixture of 2+ pure substances
Diatomic element & Monatomic element & Polyatomic
Dia: O2, H2
Mon: Na, Ar
Poly: O3, S8
Polyatomic ion
groups of atoms covalently bonded together, but the group of atoms as a whole has a charge
5Fe₂
What is the 5
Coefficient: Number in front of formula which tells how many molecules/atoms present
5Fe₂
What is 2
Subscript: Number that indicates amnt of atoms/groups of atoms in formula
(Fe₂)₂
2 Fe₂
What is an ion
Positive or negative charged atom
Entropy
Measure of disorder in system
If you burn gasoline will entropy increase or decrease
Increase becausethe energy becomes less usable
Kelvin
What is 0 degrees Kelvin known as
Basic metric unit of temp
Absolute 0
How do you change from Celcius to Kelvin
+273.15 kelvins
Temp 12000k what is that in celsius
12000 - 273.15
926.85
Changes of common states of matter
Condensation: gas to liquid
Vaporization: liquid to gas
Freezing: liquid to solid
Melting: Solid to liquid
Sublimation: Solid to gas
Deposition: Gas to solid
Metric system
How many grams in 1 kg
How many milligrams in 1g
1000g
1000 milligrams
How many kg in 25,600g
25.6 kg
Percent error formula
|observed value - accepted value| divided by accepted value times 100
Accuracy and precision
Accuracy: How close measurement is to exact value
Precision: Indicates how repeatable measurement is
Law of definite composition
Every compound is formed of elements combined in specific ratios by mass that are unique for that compound
Electron, proton, neutron what are they
Which weighs the least
Subatomic particles
Electron
A number and Z number of atom
What A and Z
A: Atomic number
Z: Protons
Niels Bohr what did he propose
Concept of principal energy levels that he envisioned as set of circular tracks on which electrons orbited
Heisenberg Uncertainty Priciple
Impossible ot know both energy and location of an electron in an atom
Pauli exclusion principle
No 2 electrons in an atom can have same address
Afbau principle
Hypothetically electrons orbiting 1 or more atoms fill lowest available energy lvls before filling higher lvls
Hund’s rule
As electrons fill sublvl, all orbitals receive 1 electron with same spin before they begin to pair
4 parts of electrons address
N- energy level (1, 2, 3, 4 distance from nucleus)
L- energy orbital or sublevel (s, p, d, f)
M- how sublevel or orbital is arranged in 3D space
S- Spin (electron spin)
What is s, p, d, f orbitals/sublvls
what is the maximum number of electrons that can be in each kind sublevel?
Sublvls inside principle lvl
S- 2
P- 6
D- 10
F- 14
Electron configuration
Ex: Carbon 6
How electrons are arranged1s2 2s2 2p2
Electron configuration for nitrogen (7 electrons)
1s2 2s2 2p3
What does [He] mean in electron configuration
Helium 1s2
Isotopes
Elements with different numbers of neutrons
Carbon- 12, Carbon- 13 and Carbon- 14 have same number of ___________ and different number of __________
Protons
Neutrons
Canutium has atomic number of 42 and atomic mass of 98 how many protons and neutrons does it have
42 protons
56 neutrons
Carbon has 6 electrons. If it loses 1 electron what kind of charge will it have
Positive
If Carbon gains 1 electron what charge will it have
Negaitive
PO4 ^-3 is an atom, ion, element, or isotope
Ion
Wavelength
Distance between 2 peaks or troughs in a wave
Frequency
Number of waves (cycles) per second that pass given point in space
What is relationship between frequency and wavelength
High frequency -> short wavelength
Small frequency -> long wavelength
What are units of frequency and wavelength
Hertz
What is h in c= hv
Wavelength
C = 3 x 10^8 m/s and wavelength is 50 m what is frequency
3 x 10^8 = 50 v
V = 6 x 10^6 hz
What did Newlands discover
Law of octaves
Law of octaves
Connection with atomic mass and chemical properties
What did Mendeleev do for creating periodic table
Elements arranged by atomic masses
Knew elements not yet discovered
Transition metals
Periodic law
Lustrous
metallic
Alkali metals
How many electrons do they lose or gain
Group 1
Very chemically reactive
Metallic and soft physical properties
Sodium, potassium, lithium, rubidium, cesium
Lose 1 electron
Alkali earth metals
How many electrons do they lose or gain
Group 2
Denser, harder, higher melting points than alkali metals
Typically donate 2 electrons
Magnesium, calcium, strontium, barium, radium
Ex: Military flares, x-rays, bones
Halogens
Group 17
More color, higher melting point, density
Most reactive out of all nonmetals
Used for halogen lights, bleach and medical uses
Noble gases
Group 18
Colorless, odorless, tasteless
Rarely react
Used for balloons, diving, neon light
Metalloids
Characteristics lying between those of metals and nonmetals
Semiconductors
Boron, silicon
How does the size of a metal atom compare to its positive ion? Its negative ion?
Positive (Cation)- Bigger
Negative (Anion)- Smaller
Ionization energy
Measures the energy required to remove an outermost electron
Trend- upper right corner
Atomic radius
Measured using x-ray diffraction. Determined by electron cloud
Trend- lower left corner
Ion size
Cation-bigger
Anion- smaller
Electron affinity
measures the energy released when an electron joins an atom
Trend- upper right corner
Electronegativity
Measure the attraction of bonded atoms to electrons?
Trend- upper right corner
Why do atoms form bonds
What part of atom is involved in bonds
Lose energy
Gain stability
Valence electron
When atoms bond, they want to have enough electrons to become like which family or group of elements
Noble gases
Polarity of a bond btwn 2 atoms depend on what
Electronegativity
What does deltaEN mean
Electronegativity
What kind of bond would exist between Na and F
Ionic
What is electrostatic force
+ and - charges in atoms that attract or repel each other
What does the single dash btwn 2 atoms mean
2 electrons shared
What does double dash btwn 2 atoms mean
2 pairs of 2 electrons shared
What does triple dash btwn 2 atoms mean
3 pairs of 2 electrons shared
Electron sea theory
All metal atoms in metallic solid contribute valence electronsto form a sea of electrons
Which does electron sea theory explain regarding metals
Luster, conductivity, ductility
Ionic compounds
Strong bonds
High melting points
Dense, brittle, hard
Good electron conductors if dissolved/molten
Ionic compounds are they good at electrical conductivity
Yes
Are ionic compounds easily broken as crystals
No
*Sigma bonds
How are they formed
What is involved in their formation
Formed by head-to-head overlapping of atomic orbitals
Single bond
Pi bonds
How are they formed
What is involved in their formation
The same phase overlap of atomic orbitals along a direction perpendicular to the internuclear axis
Found in double and triple bonds
Weaker than sigma bonds
Which bond type is stronger sigma or pi
Sigma
How many sigma and pi bonds are in
H2O, CH4, N2, HCN, O2
H2O- 2 sigma
CH4- 4 Sigma
N2- 1 sigma 2 pi
HCN- 2 sigma 2 pi
O2- 1 sigma 1 pi
Which bond would be the strongest single, double, or triple
Triple
Resonance
No single Lewis structure can totally describe how electrons are distributed
What makes a good graph
Title on top of graph
Labels on x and y axis
Units to go with labels on x and y axis
Why do we need to wear eye goggles when working with glass or liquids other than water
To protect your eyes
Why would you need to wear a lab apron during a lab
To protect from chemicals
If you have long hair why should you tie it back when working with fire
So hair doesn’t catch on fire
Why use tongs when working with glass beaker
To safely grab very hot items
What is purpose of wire gauze
Place between beaker or dish and lab burner
Inductive vs Deductive reasoning
Inductive- Begins with observation
Deductive- Begins with theory
Bonds sigma and pi
Single- 1 sigma
Double- 1 sigma 1 pi
Triple- 1 sigma 2 pi
