Matter and Materials Lecture Flashcards

Comprehensive vocabulary flashcards covering the classification of matter, atomic structure, the periodic table, chemical bonding, and types of chemical changes based on the provided lecture notes.

Mixtures

Substances that are mixed physically and are not chemically bonded to one another, keeping individual physical properties like colour and solubility.

Homogeneous mixture

A uniform mixture where all substances are in the same phase so that none of them can be clearly identified from the others.

Heterogeneous mixture

A non-uniform mixture consisting of substances in different phases or substances that can be clearly identified.

Pure substances

Matter made up of only one type of substance with no other substances or impurities.

Elements

The simplest type of pure substance that cannot be broken down by chemical reactions into any simpler types of substances.

Compounds

Substances made up of two or more elements bonded together in a fixed ratio by a chemical reaction.

Molecular formula

A representation using chemical symbols to indicate the types of atoms and subscripts to show the number of each type of atom.

Groups

Vertical columns on the Periodic Table where the number corresponds to the number of outer-shell (Valence) electrons.

Periods

Horizontal rows on the Periodic Table representing elements arranged in order of increasing atomic number ($Z$).

Semi-metals (Metalloids)

Elements close to the zig-zag line on the Periodic Table that exhibit properties of both metals and non-metals.

Atomic number ($Z$)

The number of protons and the number of electrons in a neutral atom.

Atomic mass number ($A$)

The total number of protons and neutrons in an atom's nucleus.

Nucleus

The center of the atom containing positively charged protons and neutrons with no charge.

Electron shells

The outermost regions of the atom that contain negatively charged electrons.

Energy levels

The regions outside the nucleus where electrons are arranged, indicated by values $n = 1, 2, 3 ext{…}$.

Orbitals

The most probable space where an electron can be found in an atom.

Aufbau principle

The rule stating that the lowest energy level is always occupied by electrons first when building an electron configuration.

Valence electrons

The electrons located in the outer energy level of an atom.

Lewis Diagrams

Electron dot diagrams where chemical symbols are surrounded by dots or crosses representing valence electrons.

Valency

The number of electrons an atom needs to lose or gain to reach the stability of noble gases.

Cations

Positively charged ions, typically metals, formed by losing valence electrons.

Anions

Negatively charged ions, typically non-metals, formed by gaining electrons.

Isotopes

Different atoms of the same element that contain the same number of protons but a different number of neutrons or mass number.

Physical change

A change in the state of a substance where the chemical make-up remains the same and no new substances are produced.

Chemical change

A process where a new substance is produced with properties different from the original, often difficult to reverse.

Octet rule

The principle that atoms form compounds to achieve eight valence electrons, imitating the stability of noble gases.

Covalent bonding

A chemical bond involving the sharing of a bonding pair of electrons between non-metal atoms.

Ionic bonding

A bond formed by the transfer of electrons between atoms and the subsequent electrostatic attraction.

Electrostatic force

The attraction toward one another of oppositely charged particles.

Polyatomic ions

Compound ions such as Hydroxide ($OH^-$), Carbonate ($CO_3^{2-}$), or Phosphate ($PO_4^{3-}$).

Exothermic reaction

A chemical reaction where energy is given off and the temperature of the system rises.

Endothermic reaction

A chemical reaction where energy is absorbed and the temperature of the system drops.