chemistry chapter 1 - models of the particulate nature of matter

Vocabulary flashcards covering key concepts from 1.1 particle matter 1.2 nuclear atom 1.3electron configurations 1.4 particles and 1.5 gas laws.

Monoatomic Structure

this structure consists of one singular atom (no bonds)

Moleular Structure

two or more types of atoms combined chemically

Lattice Strucutre

atoms that form a crystalline structure

what is matter classified as?

pure substance and mixture

homogeneous mixture

A mixture in which substances are evenly distributed throughout the mixture

example of homogeneous mixture

salt water - you cannot tell where the water and salt particles are

heterogeneous mixture

A mixture in which different materials can be distinguished easily

example of heterogeneous mixture

cereal in milk - you can clearly see the difference in the cereal and milk

What is a solution?

A homogeneous mixture of two or more substances (salt water)

solution particle size

less than 1 nm

What is a colloid?

A mixture containing small, undissolved particles that do not settle out. (whip cream)

colloid particle size

1nm to 1000nm

What is a suspension?

A mixture in which particles can be seen and easily separated by settling or filtration (boba)

suspension particle size

1000 nm and larger

what is an element and compound?

An element is a substance that cannot be broken down into two or more simpler substances. A compound is a substance that is made up of two or more elements in a fixed ratio.

What is the Tyndall effect?

the phenomenon where light is scattered in colloid or suspension, making the path of the light been visible.

What is distillation?

The process of heating a liquid to the boiling point, condensing the heated vapor by cooling (boiling point)

What is paper chromatography?

To separate a mixture that is on a piece of paper, measured through how strong they interact with the paper (Affinity)

What is hand picking?

To separate solid objects by hand (ham bao bao)

What is threshing?

The process of separating seed grains from the chaff. (size/weight)

What is winnowing?

The process of separating the light components from the heavier ones (rocks, pebbles)

What is seiving?

The process of separating solids with different sizes, separating the smaller to large.

What is magnetic attraction?

The process of using a magnet to separate magnetic materials.

What is sublimation?

the process in which a solid changes directly into a gas.

What is evaporation?

the process of turning liquid into vapor.

What is crystallization?

The process by which atoms are arranged to form a material with a crystal structure. (solid from liquids that have a low boiling point)

What is Sedimentation and decantation?

sedimentation- something settles in bottom of water

decantation- liquid separated by pouring off

(solubility and density)

What is loading?

the process of adding a chemical to a liquid containing fine impurities to make them clump together, become heavier, and settle out more quickly (molarity/density)

What is filtration?

the process of separating solid

particles from a liquid. (size/solubility)

What is centrifugation?

Centrifugation force is used to separate solids from liquid matter (density - the heavier materials will go down while the lighter material goes out)

What evidence based on simple observation can you think of that supports the idea that water is made from discrete particles?

The particles are loose, they overlap each other. So it follows the shape of the container.

what is an ionic bond?

a type of chemical bonding that involves the transfer of electrons between atoms, resulting in the formation of ions and opposite charges that are attracted to each other.

What is a Covalent bond?

a type of chemical bond formed by the sharing of electrons between atoms to create shared electron pairs, which results in a stable full outer electron shell for each atom.

What is a metallic bond?

a type of chemical bonding characterised by the electrostatic attraction between delocalised electrons and positively charged metal ions.

What is intermolecular force?

the attraction between molecules

What is electronegativity?

The ability of an atom to attract electrons, the stronger the electronegativity is, the greater attraction from negative to positive.

What is kinetic energy?

the movement of particles

How does the kinetic molecular theory explain the physical properties of solids, liquids, and gasses?

when temperature rises, the kinetic energy rises making physical properties of solids, liquids and gasses?

Does the type of molecule matter in terms of kinetic energy?

no, no matter what type of molecule it is, the higher the temperature, the higher the kinetic energy.

What is 0 degree celsius in Kelvin?

273.15K

what is Kevin directly proportional with?

kinetic energy. 0 kelvin (absolute 0) is = to 0 kinetic energy because there is no movement in absolute 0.

Mass number

Total number of protons and neutrons in the nucleus of an atom.

Atomic number

Number of protons in the nucleus; defines the identity of the element.

Isotopes

Atoms of the same element (same atomic number) with different numbers of neutrons, hence different mass numbers.

Atomic mass unit (amu)

Unit used to express atomic/molecular masses; 1 amu = 1/12 the mass of carbon-12.

Carbon-12 standard

Carbon-12 (12C) is the reference standard used to define the atomic mass unit.

Mass spectrometry

Analytical technique to measure masses of atoms/molecules and their isotopic abundances.

Emission spectra

Line spectra produced when atoms emit photons as electrons transition to lower energy levels.

Energy level

Quantized electron energy states in an atom; energy levels are arranged from nearest to farthest from the nucleus.

S orbital

Orbital with l=0; holds up to 2 electrons; spherical shape; one per energy level.

P orbital

Orbital with l=1; holds up to 6 electrons; three orbitals (px, py, pz) oriented along x, y, z.

D orbital

Orbital with l=2; holds up to 10 electrons.

F orbital

Orbital with l=3; holds up to 14 electrons.

Aufbau principle

Electrons fill the lowest-energy orbitals first, following a diagonal (Madelung) rule.

Pauli exclusion principle

No two electrons in an atom can have the same set of four quantum numbers; each orbital holds up to 2 electrons with opposite spins.

Hund's rule

For orbitals of equal energy, electrons occupy them singly with parallel spins before pairing.

Madelung rule (diagonal rule)

Guides the order in which orbitals are filled (e.g., 1s, 2s, 2p, 3s, 3p, 4s, 3d, …).

Ionization energy

Energy required to remove one electron from an atom or ion.

Ionization energy trend

Generally increases across a period (left to right) and decreases down a group; harder to remove electrons across a period.

Maximum electrons in energy level n

2n^2 electrons can occupy the nth energy level.

Bohr model

Early atomic model describing electrons in fixed, quantized orbits around the nucleus.

Quantum mechanical model

Modern model where electrons occupy orbitals—probability clouds solved via Schrödinger equation.

s orbital

Shape: spherical; first energy level; one s orbital per energy level (1s, 2s, 3s, …).

p orbitals (px, py, pz)

Dumbbell-shaped orbitals oriented along x, y, z axes; begin at n=2; three orbitals per energy level.

Electron configuration

Arrangement of electrons in orbitals according to Aufbau, Hund’s, and Pauli principles.

E = hf

Photon energy equals Planck’s constant times frequency; E = h f.

Wavelength (λ)

Distance between successive wave crests; used with frequency to describe light.

Frequency (f)

Number of wave cycles per second; measured in Hz.

Hydrogen line emission

Line spectrum from hydrogen due to electron transitions; includes series like Lyman and Balmer.

Atomic spectral lines

Discrete wavelengths emitted or absorbed by atoms corresponding to electron transitions.

Avogadro constant (NA)

NA ≈ 6.02 × 10^23 particles per mole.

Mole

Amount of substance containing NA particles; 1 mole = 6.02 × 10^23 entities.

Relative atomic mass (Ar)

Weighted average mass of an element's isotopes relative to 1/12 the mass of carbon-12.

Relative molecular mass (Mr)

Sum of the relative atomic masses of atoms in a molecule.

Molar mass (M)

Mass of one mole of a substance (g/mol).

Empirical formula

Smallest whole-number ratio of elements in a compound.

Molecular formula

Actual number of each type of atom in a molecule; may be a multiple of the empirical formula.

Mass percent composition

% by mass of an element in a compound: (mass of element in formula / molar mass of compound) × 100%.

Avogadro's Law

At the same temperature and pressure, equal volumes of gases contain equal numbers of moles.

van der Waals forces (London dispersion)

Intermolecular forces causing deviations from ideal gas behavior; more significant for larger, polarizable molecules.

Polar molecules

Molecules with an uneven distribution of electron density, creating a dipole moment.

Non-polar molecules

Molecules with even electron distribution and no permanent dipole moment.

Elastic collisions

Collisions between gas particles that conserve total kinetic energy (ideal gas assumption).

Ideal gas assumptions

Gas particles are point particles, have no volume, exert no intermolecular forces, and collide elastically.

STP (Standard Temperature and Pressure)

Standard conditions for gases; commonly 0°C (273 K) and 1 atm (101.3 kPa).

Real gases vs. ideal gases

Real gases deviate from ideal behavior due to intermolecular forces and finite molecular size.

Molar volume of an ideal gas

Volume occupied by one mole of an ideal gas at STP: 22.4 L.

Dipole moment

Vector quantity indicating molecule polarity due to uneven charge distribution.

Mass number

Total number of protons and neutrons in the nucleus of an atom.

Atomic number

Number of protons in the nucleus; defines the identity of the element.

Isotopes

Atoms of the same element (same atomic number) with different numbers of neutrons, hence different mass numbers.

Atomic mass unit (amu)

Unit used to express atomic/molecular masses; 1 amu = 1/12 the mass of carbon-12.

Carbon-12 standard

Carbon-12 (12C) is the reference standard used to define the atomic mass unit.

Mass spectrometry

Analytical technique to measure masses of atoms/molecules and their isotopic abundances.

Emission spectra

Line spectra produced when atoms emit photons as electrons transition to lower energy levels.

Energy level

Quantized electron energy states in an atom; energy levels are arranged from nearest to farthest from the nucleus.

S orbital

Orbital with l=0; holds up to 2 electrons; spherical shape; one per energy level.

P orbital

Orbital with l=1; holds up to 6 electrons; three orbitals (px, py, pz) oriented along x, y, z.

D orbital

Orbital with l=2; holds up to 10 electrons.

F orbital

Orbital with l=3; holds up to 14 electrons.