Periodic Table of Elements

Study Notes

Elements in the same group have the same number of valence electrons, resulting in similar chemical and physical properties.
The number of electrons in a shell is the same as the number of the period.
The atomic number of an element is the total number of electrons in all its shells.
Mendeleev arranged the periodic table according to relative atomic mass in increasing order, leaving gaps for undiscovered elements.
The modern periodic table is organized according to atomic number.

Displacement reactions: A + BC → AC + B, where a more reactive metal displaces a less reactive metal.
Metals react with oxygen to form metal oxides through oxidation reactions.
Oxidation and reduction can be explained in terms of gain or loss of oxygen.
Metals react with other substances to form positive ions, with reactivity related to the tendency to form positive ions.

The reactivity series is a list of metals in order of their reactivity: potassium, sodium, lithium, calcium, magnesium, aluminium, carbon, and zinc.
Metals that lose electrons more readily are more reactive.
Group 1 metals react similarly, losing an electron to form a positive ion with a stable electronic configuration.
Group 1 elements become more reactive as they move down the group due to the larger atomic size, making it easier for electrons to leave.

Metals react with water and dilute acids, with more reactive metals reacting more vigorously.
Lithium, sodium, and potassium react with water, producing hydrogen, heat, and a colorless solution.
Potassium reacts extremely rapidly, producing sparks.
Acids react with some metals to produce salts and hydrogen.

Rust is also known as hydrated iron oxide, formed through the reaction of iron, water, and oxygen.
Corrosion is the destruction of materials by chemical reactions due to environmental factors.
Both air and water are necessary for iron to rust.
Sacrificial protection involves using a more reactive metal to react with air and water, protecting the metal or iron.
Alloying involves mixing another metal that won't rust, while physical protection involves covering the iron to prevent air and water from reaching it.