Flashcards: Chemistry Matter and Atomic Structure — 50 cards

How is matter classified?

Matter is classified as pure substances or mixtures.

What defines an element?

An element contains only one type of atom.

What defines a compound?

A compound contains two or more elements chemically joined.

What distinguishes a homogeneous mixture?

It has uniform composition.

What distinguishes a heterogeneous mixture?

It has distinguishable components or phases.

How do qualitative properties differ from quantitative?

Qualitative properties are described without numerical measurement.

How do quantitative properties differ from qualitative?

Quantitative properties are expressed through measurement.

What differentiates extensive from intensive properties?

Extensive properties depend on the amount of matter, intensive do not.

How are particles arranged in a solid compared to a gas?

Solids have closely packed particles, gases have widely separated particles.

What shape and volume characteristics does a liquid have?

A liquid has a defined volume but takes the container's shape.

What distinguishes plasma from solids, liquids, and gases?

Plasma contains charged particles.

What type of heat change is melting classified as?

Melting is an endothermic change that absorbs heat.

Which phase changes release heat during exothermic processes?

Condensation and solidification release heat.

What do heating and cooling curves show about phase changes?

They relate temperature and time to phase changes while energy is exchanged.

What is a solution in chemistry?

A mixture of a solute dissolved in a solvent.

What defines a dilute solution?

It contains little solute.

What defines a concentrated solution?

It contains more solute than a dilute solution.

What is a saturated solution?

It contains the maximum dissolved solute under specified conditions.

What is a supersaturated solution?

It contains more dissolved solute than a saturated solution under the same conditions.

What does concentration measure?

How much solute is dissolved in a specific amount of solvent.

How is mass/mass percentage calculated?

$\% m/m = \frac{\text{mass of solute}}{\text{mass of solution}} \times 100$

How is parts per million (ppm) calculated?

$ppm = \frac{\text{amount of solute}}{\text{amount of solution}} \times 10^n$

Which atomic model introduced the concept of energy levels?

Bohr's atomic model introduced energy levels.

What is electromagnetic radiation characterized by?

Wavelength λ and frequency ν characterize electromagnetic radiation.

What formula relates wave speed, wavelength, and frequency?

Wave speed v equals wavelength λ times frequency ν: $v = \lambda\nu$.

What is the speed of light in vacuum expressed as?

The speed of light in vacuum is $c = 3 \times 10^8\ \text{m/s}$.

What does an absorption spectrum show?

An absorption spectrum shows wavelengths absorbed by a substance.

What does an emission spectrum show?

An emission spectrum shows wavelengths emitted by a substance.

What is the formula for the mass number A?

$A = p + n$

How is the neutron number n calculated?

$n = A - Z$

What does the atomic number Z represent?

The number of protons in the nucleus.

What distinguishes a neutral atom from a cation?

A neutral atom has equal protons and electrons, a cation has lost electrons.

What does the principal quantum number n identify?

The energy level of an electron.

What does the secondary quantum number l identify?

The sublevel of an electron.

What is the range of l for a given principal quantum number n?

From 0 to n − 1.

How many electrons can the s sublevel hold?

2 electrons.

What does electron configuration describe in an atom?

How electrons are arranged in an atom.

Which rule states lower-energy orbitals fill first?

The Aufbau principle.

What does Hund's rule say about electron placement?

Electrons occupy equivalent orbitals singly before pairing.

What is the Pauli exclusion principle regarding electrons in one orbital?

Maximum two electrons with opposite spins per orbital.

What is the filling order of orbitals starting from 1s?

1s → 2s → 2p → 3s → 3p → 4s → 3d → 4p → 5s → 4d → 5p → 6s → 4f → 5d → 6p → 7s.

How many electrons does a neutral oxygen atom have?

Eight electrons.

What is the electron configuration of neutral oxygen?

1s² 2s² 2p⁴.

How many groups or families does the periodic table have?

The periodic table has 18 groups or families.

How are the periods arranged in the periodic table?

Periods are arranged as rows in the periodic table.

Into which three categories are elements classified?

Elements are classified as metals, metalloids, or nonmetals.

What is ionization energy?

Ionization energy is the energy required to remove an electron.

What does electronegativity measure?

Electronegativity measures an atom’s tendency to attract electrons.

What atomic property is linked to a smaller atomic radius and greater ionization energy?

Greater nuclear attraction is linked to a smaller atomic radius and greater ionization energy.

Which element comparison illustrates greater nuclear attraction effects?

The comparison between lithium (Li) and fluorine (F) illustrates greater nuclear attraction effects.