Chemistry

Structure of an atom:

  • neatrons and protons in the nucleus, and electrons on the outer shells


Periodic table:

  • Elements arranged by increasing atomic number

  • Groups indicate elements with similar chemical properties

  • Periods show the number of electron shells in the atoms

groups: down

periods: across


The 3 main groups are:

Metals:

  • Typically conduct electricity and heat, have a shiny appearance, and are malleable.

Non-metals:

  • Generally dull in appearance, poor conductors of heat and electricity, and tend to be brittle in solid form.

Metaloids:

  • Typically have intermediate properties between metals and non-metals, exhibiting characteristics such as semi-conductivity and lustre that can vary based on their specific configurations.


Electron Shells:

2, 8, 16, 32

Matter - Electron shells and orbitals

Chemical or physical change:


Atomic radius:

  • Is the distance from the atom's nucleus to the most outermost shell.

  • represents the size of an atom

    Atomic Radius In The Periodic Table

Reactivity:

  • How easily an atom loses or gains an electron


Electronegativity:

  • A measure of an atom's ability to attract and hold onto electrons in a chemical bond.


Ionic Bonding:

  • Ionic bonding is when a metal transfers electrons to a non-metal, forming oppositely charged ions that attract each other.


  • Ionic bonding happens between a metal and a non-metal.

  • Metals lose electrons to become positively charged ions (cations).

  • Non-metals gain electrons to become negatively charged ions (anions).

  • Electrons are transferred from the metal to the non-metal.

  • Oppositely charged ions attract each other due to electrostatic forces.

  • This forms a strong ionic bond and a giant lattice structure.

  • Ionic compounds usually have high melting and boiling points.

  • They conduct electricity when dissolved in water or molten, not when solid.

Understanding Ionic Bonds | The Science Blog

Ions:

  • Ions are atoms or molecules that have gained or lost electrons, resulting in an electrical charge.


Cation vs Anion:

  • Cations are positively charged ions formed when an atom loses electrons.

  • Anions are negatively charged ions formed when an atom gains electrons.


Naming ionic compounds:

  • Name + name-ide (remove “ine” from name)

eg: Cl⁻ becomes chloride, and O²⁻ becomes oxide.

eg: Al 3+ p 3- = Al3 P3 = Al P


Bondning pairs:

  • single, double, triple

  • electron dot diagram