Go on. Explore!

lvl 0 • 0 xp

lvl 1

Home Market Decks Interests

AP Chemistry Unit 1

memorize.ai (lvl 286)

(0)

48 cards

()

Section 1

Preview this deck

precision

Front

1 / 48

Chemistry Science

0.0

0 reviews

5			0
4			0
3			0
2			0
1			0

Active users

All-time users

Favorites

Last updated

6 years ago

Date created

Mar 1, 2020

Cards (48)

Section 1

(48 cards)

precision

Front

a term that refers to how close a series of measurements are to one another or how reproducible they are

Back

pure substance

Front

elements or compounds that will always have the same composition

Back

percent difference

Front

- accuracy % difference = ((|E₁-E₂|)/(½(E₁+E₂))) x100

Back

paper/column chromatography

Front

- separation of homogenous mixtures (solutions) - based on attraction of the molecules in the solution for the molecule in the mobile phase - we have to consider the molecule's polarity

Back

excited state

Front

(n>1) electron energy increases until ionized

Back

multiple proportions

Front

John Dalton - If two elements (A and B) form more than one compound, the masses of B that can combine with a given mass of A are in ratio if small whole numbers

Back

ol drop experiment

Front

What Millikan did was put a charge on a tiny drop of oil, and measured how strong an applied electric field had to be in order to stop the oil form falling - he noticed that the charge was always a multiple of -1.6 x 10⁻¹⁹ C (coulombs are a quantity of electrical charge), the charge on single electron

Back

element

Front

the fundamental chemical substances from which all other substances are made

Back

half-life

Front

1) time it takes for half of a given amount of radioactive isotope to undergo decay 2) rate of decay is proportional to the # of nuclei present 3) rate of decay = kN↓t - k = rate constant - N↓t = amount at time (t) 4) t↓½ = ln2/k = 0.693/k 5) ln(N↓t/N↓0) = -kt 6) N↓t = N↓0e↑-kt - N↓t = amount at time (t) - N↓0 = initial amount

Back

percent error

Front

- precision % error = ((|your result − accepted value|)/ (accepted value)) × 100

Back

milli

Front

10⁻³

Back

neutron

Front

1) electrically neutral, zero charge 2) about the same mass as a proton, 1.0087 amu 3) found in the nucleus 4)number of neutrons determines the isotope

Back

significant figures

Front

In any reposted measurement, the non-place-holding digits that indicate the precision of the measured quality.

Back

John Dalton

Front

- the law of multiple proportions -> When two elements (call them A and B) form two different compounds, the masses of element B that combine with 1 gram of element A can be expressed as a ratio of small whole numbers -> Dalton used this theory to justify that atoms really are individual particles that can be broken down - atomic theory 1) each element is composed of tiny, indestructible particles called atoms 2) all atoms of a given element have the same mass and other properties that distinguish them from the atoms of other elements 3) atoms combine in simple, whole-number ratios to form compounds 4) atoms of one element cannot change into atoms of another element. In a chemical reaction, atoms only change the way that they are bound together with other atoms

Back

atomic number

Front

number of protons

Back

Robert Millikan

Front

oil drop experiment - determined the size of the charge on an electron -> -1.6 x 10⁻¹⁹ C -determined the mass of an electron -> 9.1 x 10⁻³¹ kg

Back

nano

Front

10⁻⁹

Back

isotope

Front

Atoms of the same element that contain different numbers of neutrons 1) particles are turned onto positive ions, accelerated, and then deflected by a magnetic field 2) the resulting path of ions depends on their mass/charge ratio (m/Z) 3) large m/Z value deflected least - We identify isotopes by their mass number (A), which is the total number of protons and neutrons

Back

filtration

Front

- separation of heterogeneous mixtures - based on particle size

Back

molecular formula

Front

- molecular formula = empirical formula ∙ n - n = (molar mass)/(empirical formula mass)

Back

definite proportions

Front

Joseph Proust - in a pure compound, the proportions of atoms by mass are always the same

Back

Ernest Rutherford

Front

- Gold Foil Experiment -> alpha particle (2 protons and 2 neutrons bonded together) bombardment of gold foil

Back

Neils Bohr

Front

- explained the formation of the emission spectra (for hydrogen only) 1) electrons travel around the nucleus in a circular orbit 2) orbits are at a fixed distance, "quantized" 3) potential energy of an electron is related to the distance from the nucleus 4) absorption of a photon excites the electron to a higher level 5) an electron that emits a photon of light falls to a lower level

Back

atomic mass unit

Front

(amu), one amu is equal to 1/12 the mass of a carbon-12 atom - 1.66 x 10 ⁻²⁴

Back

micro

Front

10⁻⁶

Back

emission spectrum

Front

- shows the specific frequencies of light emitted by a specific atom that is being excited - atoms can be identified by the light they emit, by their unique emission spectrum

Back

percent composition

Front

- % by mass of elements in a compound % comp = (mass of the part/mass of the whole) x100

Back

JJ Thompson

Front

- 1897 discovered the electron, the first subatomic particle - determined the charge to mass ratio of an electron -> -1.76 x 10⁸ C/g - used the cathode ray tube. He observed: 1) cathode rays traveled in straight lines 2) cathode rays were deflected by a magnetic field 3) the rays were deflected away from a negatively charged object 4) all metals produce these rays 5) he proposed that atoms consist of small, negative electrons embedded in a massive, positive sphere - Plum pudding model

Back

compound

Front

A substance that contains two or more elements chemically combined in a fixed proportion

Back

energy of an electron

Front

- n = principle quantum number - E↓n = (-2.18 x 10⁻¹⁸ J)/(n²) - ∆E = E↓final - E↓initial

Back

ion

Front

1) ions are atoms that have lost or gained electrons - # electrons /=/ # protons - e⁻ > p⁺ : (-) charged (anion) - e⁻ < p⁺ : (+) charged (cations)

Back

cathode ray tube

Front

Back

heterogeneous mixture

Front

- can see the different substances - nonuniform composition

Back

ground state

Front

(n=1) electron has lowest (most negative) energy

Back

accuracy

Front

a term that refers to how close a measured value is to the actual value

Back

classifying matter

Front

Back

EM wave

Front

c = λ∙v - v = frequency in Hertz (Hz) - c = speed of light 3.0 x 10⁸ m/s - λ = wavelength in meters (m) E↓photon = h∙ν & E↓photon = (h∙c)/(λ) - h = Plank's constant = 6.626 x 10⁻³⁴ J∙s - E = mc²

Back

mass number

Front

# of protons + # of neutrons

Back

empirical formula

Front

the lowest whole-number ratio of atoms of the elements in a compound

Back

mole (mol)

Front

a unit defined as the amount of material containing 6.02 x 10²³ (Avogadro's number) particles

Back

conservation of mass

Front

Antoine Lavoisier - in a chemical reaction, matter is neither created of destroyed, only rearranged

Back

gold foil experiment

Front

Observations -> Conclusions 1) most alpha particles passed through gold foil -> atom is mostly empty space 2) small percentage has a slight deflection -> nucleus is positively charged 3) tiny percentage bounced straight back -> mass of the atom is in the nucleus

Back

mass spectrometer

Front

Tool used to measure masses of atoms or molecules in their percent abundance 1) inject sample 2) heat to vaporize sample 3) electron beam ionizes sample 4) particles accelerated into magnetic field 5) magnetic field separates particles based on mass/charge ratio

Back

proton

Front

1) positively charged particle 2) part of the dense nucleus along wth neutrons 3) mass of 1.0073 amu per proton, about 2000 times more massive than an electron 4) along with neutrons in the nucleus make up most of the mass of the atom 5) along with neurons in the nucleus make up a small part of the atoms overall volume 6) scientists have agreed to identify elements by atomic number, which is the number of protons each atom has. Symbol of atomic number is (Z)

Back

average atomic mass

Front

the average mass of all isotope of the element as they occur in nature

Back

electron

Front

1) electrons occupy 3D regions of space called the orbitals that surround the nucleus 2) negatively charged (-1 charge) 3) 1/2000 the mass of a proton, 5.5 x 10 ⁻⁴ amu 4) loss, gain, and sharing of electrons important in many chemical reactions

Back

distillation

Front

- separation of homogenous mixtures (solutions) - based on different boiling points

Back

homogeneous mixture

Front

a mixture where the composition is the same throughout

Back