CHEM EXAM!! Flashcards
What is density?
The amount of space (volume) and object takes up in relations to how many particles (mass) is in the object.
Precision
Degree to which repeated measurements under unchanged conditions show the same results.
Accuracy
Degree of closeness of a quantity to the actual (true) value.
What is mass?
A quantity which measures how much matter or particles are inside a certain object. Measure of the “insides” of something
What is volume?
The amount of space that an object takes up. Its what contains the elemnts and parts of that object.
Metric conversions prefixes
M-mega 10^6, k-kilo 10^3, h-hecto 10^2, da-deca 10^1, B-base, d-deci 10^-1, c-centi 10^-2, m-milli 10^-3, u-micro 10^-6, n-nano 10^-9
Whats an volumetric flask?
Flask with round sides
What is molar mass?
The mass of 1 mole of any chemical compound or element. 6.02x10^23 molecules, atoms, etc. Each atom times the mass on there periodic table, then add all together.
Erlenmeyer flask
Flask with straight sides
What is PASS?
P-pull pin
A-aim at base of fire
S-squezze
S-sweep back and forth
What can you observe in a physical change?
1: State 2: Shape 3:Size
Chemical property
Can be observed by changing the identity of the substance.
Physical change
Changes form of the substance without changing the identity. Chemical properties stay the same.
What can you observe in a chemical change?
light, heat, cooling, color, odor, bubbles, solid, smoke
What is an Alloy?
homogeneous mixture of metals
Element
composed of a single atom ( smallest particle of an element will obtain all of its properties)
Compounds:
Composed of two or more elements combined together in a specific ratio
Physical property
Can be observed without changing the identity of a substance.
Chemical change
Changes the identity of a substance. Products have different properties.
Homogeneous mixture:
uniform in composition every portion is like every portion (solution)
`Observation
Anything you know based on your five senses.
Inference
An educated guess based on your five senses.
Heterogeneous mixture:
composition varies from position to position
Cation
positive charge
Exothermic
Gives off heat energy. Ex: hand warmers
Endothermic
Uses heat energy Ex: ice pack
Solute
A substance dissolved in a solution. Ex: Salt
Solvent
Substance that dissolves a solute. Ex: water
Solution
Homogenous mixture that may contain solid, liquid, gas.
Filtrate
Material, usually liquid, that has passed through a filter.
Precipitate
Formation of a solid in a solution.
Law of conservation of mass
Mass is neither created nor destroyed, only changed.
Anion
negative charge
What is an isotope
elements that have a difference in their neutrons and therefor mass/stability
For anion naming in isotopes
Drop ending of the element and ad ide and then ion
Filtration
Filtrate passes through filter, residue is left behind.
Evaporation
Heat the solution until solvent evaporates leaving behind the solid residue.
For cation naming
Add ion to the element name
For transition metal naming
there are multiple charges so we use roman numerals name (numeral) ion
Atomic mass
Weighted average of all the isotopes for an element. amu
Relative abundance
The frequency of the isotopes occurring in nature.
Ous ending
a lower charge
Ic-ending
higher charge
What is a nuclear reaction
Changes the composition of the atoms nucleus due to the nucleus being unstable
Radiation
Emission of energy as electromagnetic waves or subatomic particles.
Radiocativity
-spontaneous emission of radiation from a atom
Nuclear stability
-associated with p+ and n*
-strong nuclear forces
-p+ repelling p+ electro magnetic repulsion
-n have no electrical repulsion so they act as a glue holding the nucleus together
- elements 1-20 p=n stable
-past 20 more n required
-past 80 radioactive due to p and n balance.
Properties of Alpha radation
-2 p 2 n
-mass of 4 amu
-charge +2
-when you gain/lose the element changes
-slower due to a larger mass
-when their is to many p and high repulsion
Beta radiation:
-high speed e- from nucleus
-n split into p and e
-mass o
-charge -1
-occurs when an n needs to be kicked out
Democritus
Gave the term “atom”. Current def: An atom is the smallest particle of an element that retains the chemical identity of the element.
Dalton
Used Lavoisier’s law of conservation of matter and Proust’s law of constant comp. the create his 4 point theory. 1. All matter consists of tiny particles called atoms. 2. When elements react, the combine in simple whole number ratios. 3. Atoms are indestructible and unchangeable. 4. Elements are identified by their atoms. All atoms of a given element are identical. 3 and 4 are now proven incorrect.
Franklin
Stationary electric charge, two kinds of electrical charge (+ and -).
Thomson
Experimented with currents of electricity inside empty glass tubes (cathode ray tubes). Discovered sum atomic particles. The cathode rays were made up of electrons.
Gamma Radation
-high energy
-not made of particles
-mass 0 charge 0
-electromagnetic radiation
-typically goes with alpha/beta
Fission
splitting
-large nucleus breaks into 2 or more small pieces
A+B –> C
-emission/decay
Fusion
combine
-small moving particles fuses with the nucleus
A+B=C
-capture/bombard
Half life
average amount of time for half a sample to decay
Bequerel/Curies
Discovered radiation from uranium, radium, and polonium. Showed that atoms could be changed. Alpha, beta, gamma.
Milikan
Oil drop experiment. Measured the charge and mass of an electron. Found mass and charge of the electron.
Rutherford
Gold foil experiment. Discovered that the atom has a dense, positive center and most of the atom is empty space. Discovery of proton.
Chadwick
Discovered the neutron.
Bohr
Flame tests and spectrum. Electrons travel in definite energy levels (orbitals) instead of random motion.
Schrodinger
Concept of electron clouds.
Atomic emission spectrum
-spectrum with only certain colors
-finger print of an element
Continuous Spectrum
contains all colors on in order of freq. /wavelength
Max Planck
studied light emitted from heated objects
connected energy and frequency
Quanta
atoms can gain or lose energy in specific amounts
E(quanta)=hv
E- quanta
h-planks constant 6.626 * 10 -34
v-frequency (hz)
Quantum theory
light energy comes in specific amounts (packets)
photons- packets of em radiation
photoelectric effect-electrons are ejected from surfaces of metals when certain frequencies of light shine on metals
Light production
1: e at ground state lowest energy level and most stable
2: add energy
3: e jump to a higher energy energy state excited state
4: e drop back down and resale the added energy as light
The energy levels
there are 7
each energy level has sub levels
s(low e-),p,d,f(high e-)
2 electrons max per orbital
Electromagnetic radiation
Forms of energy that exhibit wave like behavior as it travels
Order of electro. radiation in order of increasing frequency
radio, radar, micro,infrared, visible, ultraviolet, x-ray, gamma
Wavelength
Shortest distance between equivalent points on a continuous wave. Crest to crest etc.
Quantum numbers
n=principle energy level
L= energy sub level/shape (s,p,d,f)
ml= orientation in space p^x, p^x
ms= electron spin
Bohr’s energy equation
E=Rh(1/ni-1/nf)
e-energy of jump/fall (J)
Rh-rydbergs constant 2.18 *10^18
ni=intail enery level
nf=final energy level
Frequency
Number of waves that pass a given point per second. Hertz. 1Hz=1wave/1sec
Amplitude
Height from rest position to crest/ trough.
Speed
s=wavelength x frequency (c= 3.00x10^8 m/s)
Liters in mole conversions
22.4 L
Particles in mole conversions
6.02 x 10^23 particles
Paula Exclusion Principle
- an orbital can only hold 2 electrons and they must have opposite spin
Aufbau Principle
electron fill lowest energy orbitals first
Hunds Rule
electrons fill equal energy orbitals one at a time only pairing when they have too ( e- repel e-)
