Test 1 Study Guide Flashcards
What is a measurement?
A comparison against an exact invariable standard.
1. Size and magnitude (number)
2. Standard of comparison (unit)
3. Indication of uncertainty
SI/Base Unit: Length
meter; meter
SI/Base Unit: Volume
cubic meter (m^3); Liter
SI/Base Unit: Time
seconds; seconds
SI/Base Unit: temperature
Kelvin; K,C,F
How do you estimate digits on an analog instrument?
Estimate the last digit
How do you estimate digits on a digital instrument?
The last digit is already an estimated digit
What is the difference between precision and accuracy?
Precision: The reproducibility of a measurement (how close your measurements are to each other).
Accuracy: How close you are to the true value.
What do precision and accuracy depend on?
Precision: depends on how good you are at using the instrument.
Accuracy: Depends on the instrument you are using. The smaller the divisions, the more accurate.
What is an exact number?
Numbers arrived at by direct count or are a defined relationship.
1. $12.52 / 2 dozen
2. 1000g = 1kg
Rules of significant figures.
- Start counting with the first non-zero digit
- All non-zero numbers are significant
- Captive zeroes: always significant
- Leading zeroes: never significant
- Trailing zeroes: significant after decimal, not significant if no decimal
Rules of addition/subtraction with significant figures.
Least number of decimal places
Rules of multiplication/division with significant figures.
Least number of significant figures
Metric Prefix: Tera
T; 10^12
Metric Prefix: Giga
G; 10^9
Metric Prefix: Mega
M; 10^6
Metric Prefix: kilo
k; 10^3
Metric Prefix: hecto
h; 10^2
Metric Prefix: deca
da; 10^1
Metric Prefix: deci
d; 10^-1
Metric Prefix: centi
c; 10^-2
Metric Prefix: milli
m; 10^-3
Metric Prefix: micro
µ; 10^-6
Metric Prefix: nano
n; 10^-9
Metric Prefix: pico
p; 10^-12
SI/Base Unit: mass
kilogram; gram
1 mL = ___ cm^3
1
The formula for density?
density = mass / volume
SI/Base Unit: Density
kg/m^3
Liquids/solids: g/cm^3 or g/mL
gas: g/L
What is temperature?
A measurement of the average kinetic energy of particles
The formula for Celsius to Kelvin?
K = C + 273.15
The formula for Celsius to Fahrenheit?
F = (1.8*C) + 32
The formula for Fahrenheit to Celsius?
C = (F - 32) / 1.8
What is energy?
The capacity to do work (the process of causing matter to move against a force).
What is potential energy?
The energy that an object possesses because of its position, composition, or condition. Ex. water at the top of a hill
What is kinetic energy?
The energy of motion. Ex. water rushing down a hill
What is chemistry?
The study of matter, its composition, structure, states, properties, and the changes it undergoes.
What is matter?
Anything that has mass and takes up space.
What are the three states of matter?
Solid, Liquid, Gas
What is a solid?
A state of matter with definite shape and definite volume. The particles are close together (fixed) and move very slowly. The interactions between atoms are very strong.
What is a liquid?
A state of matter with its shape being the same as the container it is in and its volume being definite. The particles are close together (random) and move at a moderate pace. The interactions between atoms are strong.
What is a gas?
A state of matter with its shape being the same as the container it is in and its volume being the same as the container it is in. The particles are far apart (random) and move at a very fast pace. The interactions between atoms are almost none.
What is an atom?
The smallest particle of an element that still has properties of that element.
What is a molecule?
2 or more atoms joined together by a chemical bond.
What is a pure substance?
A substance made up of only one type of component.
What is a mixture?
Two or more particles that are combined, but not chemically.
What is the difference between an element and a compound?
An element is only one type of atom and cannot be chemically broken down. A compound is 2 or more elements that are chemically bound together in a definite proportion.
What is the difference between a homogeneous and heterogeneous mixture?
A homogeneous solution is uniform throughout and a heterogeneous solution is not uniform throughout.
What is the difference between a physical and chemical change?
A physical change can be observed without changing the identity of the substance; whereas, a chemical change can only be observed by changing the identity of the substance.
What are examples of physical changes?
Luster, Melting/boiling point, phase of matter, density, solubility, odor, shape
What are examples of chemical changes?
Flammability, pH, combustibility, reactivity, ability to oxidize (rust)
What laws did Dalton know?
- Law of Conservation of Mass
- Law of Definite Proportions
- Law of Multiple Proportions
What is the law of conservation of matter?
Matter cannot be created or destroyed.
What is the law of definite proportions?
(law of constant composition) All samples contain the same elements in the same proportion by mass. H_2O: 11% H and 89% O.
What is the law of multiple proportions?
When 2+ elements react to form more than one compound, a fixed mass of 1 element will react with the other element. CO: 12g C, 16g O. CO_2: 12g C, 32g O.
What is Dalton’s Atomic Theory?
- Matter is composed of atoms
- Elements are only one type of atom
- Each element has different properties
- A compound is 2 or more atoms
- Atoms are not created or destroyed
What did JJ Thomson discover?
The electron, plum pudding model of the atom
Who discovered the electron?
JJ Thomson
What did Robert Millikan discover?
Charge of the electron; -1.6 x 10^-19 C
Who discovered the charge of the electron?
Robert Millikan
What did Ernest Rutherford discover?
Proton; modern nuclear atom
Who discovered the proton?
Ernest Rutherford
What did James Chadwick discover?
Neutron
Who discovered the neutron?
James Chadwick
What is the mass number?
(A) number of protons + neutrons
What is the atomic number?
(Z) number of protons (electrons in a neutral atom)
What is an isotope?
Atoms with the same atomic number (Z), but different mass numbers (A).
What is the difference between atomic mass and atomic weight?
Atomic mass is the mass of a single atom; whereas, atomic weight is the average mass of all isotopes.
What is the atomic weight of an element closest to?
The mass of the most abundant isotope.
The formula for atomic weight?
Σ (fractional abundance) x (isotope mass)
What is a mole? What number defines it?
The number of carbon atoms in exactly 12 grams of carbon-12. Avogadro’s number: 6.022 x 10^23 particles = 1 mol
What is the molar mass?
The mass of 1 mole of an element. It is the atomic mass expressed in grams. Also called formula weight and molecular weight.
What do the subscripts in a formula show?
The moles of each element in 1 mole of compound
What are the parts of a wave?
- Amplitude
- Wavelength (λ)
- Frequency (ν)
What is amplitude?
The vertical height (center point to crest or trough) of a wave and is related to the energy the wave is carrying (light intensity).
What is wavelength (λ)?
The distance between successive crests on the wave (or any two analogous points)
What is frequency (v)?
The number of crests that pass a given location per second, usually reported in Hz.
What is the order from lowest energy to highest energy on the electromagnetic spectrum?
Radio, Microwave, Infrared, Visible (ROYGBIV), Ultraviolet, X-ray, Gamma-ray
What is the order from lowest frequency to highest frequency on the electromagnetic spectrum?
Radio, Microwave, Infrared, Visible (ROYGBIV), Ultraviolet, X-ray, Gamma-ray
What is the order from longest wavelength to shortest wavelength on the electromagnetic spectrum?
Radio, Microwave, Infrared, Visible (ROYGBIV), Ultraviolet, X-ray, Gamma-ray
What is the speed of light in a vacuum?
(c) 3.00 x 10^8 m/s
The formula that relates wavelength and frequency to speed?
c = λ*v
What is constructive interference?
When two waves are aligned in such a way as to always add to give increased crest height (amplitude).
What is destructive interference?
When two waves are aligned in such a way as to cancel out each other’s effect.
What did Einstein conclude from his photoelectric effect experiment?
Einstein concluded that light energy is delivered to the atoms in packets called quanta or photons and that the energy of a photon of light is directly proportional to its frequency, or inversely to its wavelength.
The formula that relates the energy of a photon to frequency?
E = h * v
Energy = J
h = J*s
v = Hz
The formula that relates the energy of a photon to wavelength.
E = (h*c) / λ
Energy = J
h = J*s
c = m/s
λ = m