Chemistry

Flashcards covering the classification of matter, atomic structure details, ion types, and periodic table organization based on lecture notes.

Atom

The smallest particle of an element, made of protons, neutrons and electrons.

Element

A puro substance made of only one type of atom.

Compound

A substance made when $2$ or mor different elements are chemically bonded togemer.

Mass number

The total number of protons + ncutrons in onc atom; always a whole number.

Atomic mass

The average mass of all the isotopes of an element, usually a decimal number found on the periodic table; for example, chlorine has an atomic mass of about $35.5$.

Stable shell atoms

Atoms that have a full outer shell, usually noble gasses (Group 18), and are unreactive as they don't have to gain or loose electrons.

Ion

An atom that has gaincel or lost electrons and therefore has an overall electric charge.

Cation

A positive ion, formed when an atom looses electrons.

Anion

A negative ion, formed when an atom gains electrons.

Ground State of an atom

When an atoms electron are in their normal, lowest energy arangement.

Exited State of an atom

When an electron absorb) and moves to a higher energy level further from the nucleus; considered an unstable atom.

Valancy

The number of electrons an atom needs to gain or loose or share to achieve a full outer Shell (stable); it shows how many bonds an atom can form with other atoms.

Mandelecko / Mandeleeve

A scientist who left gaps in his periodic table because he believed some elements hadn't been discovered yet; he predicted an undiscovered element called "ika - Silicon".

ika - Silicon

An undiscovered element predicted by Mandeleve which was later found and named germanium.

Periodic law

States that when elements are arranged in order of increasing atomic number, their physical and chemical properties repeat in a regular pattern.

Period

A horizontal row where elements have the same number of electron shells.

Group (Column)

A vertical column where elements have the same number of outer (valance) electrons and similar chemical proportics.

Metals

Elements found on the left and centre of the periodic table, such as iron, sodium, and calcium.

Non metals

Elements found on the right side of the periodic table, such as oxegyn, nitrogen, and chlorine.

Metal aids

Elements found along the zig zag staircase line between metals and non metals, such as silicon, boron, and arsonic.

Group 1 (Alkali)

Elements with high thermal and electrical conductivity, lustre, ductility, and mallcability that have a single electron in the outer shell.

Group 2 (Alkaline Earth)

The second most reactive elements; they are shiny, have low density, melting points and boiling points, and have $2$ electrons in outer most shell.

Group 7 (Halogens)

Highly reaction elements with $7$ valance electrons in the outer shell that all form acids when combined with hydrogen and combine with metals to form salts.

Group 8 (Noble gasses)

Sometimes group $0$; these are odorless, colourless, non flammable, monotone (dont bond), extremely stable elements with $8$ in outershell.

Lanthanide

A group of $15$ chemical elements, also called rare earth metals, that are silver in colour and can tarnish when exposed to oxygen.

Actinides

Radioactive elements that release energy upon radioactive decay.

H2O

The chemical formula for Water.

CO2

The chemical formula for Carbon dioxide.

NaCl

The chemical formula for Sodium chlorido.

CH4

The chemical formula for Methane.

HCl

The chemical formula for Hydrochloric Acid.