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PTE Science Test

Ionization Energy:

The amount of energy required to remove an electron from an isolated atom or molecule.

Helium has the highest Ionization Energy meaning it is more difficult it is to remove an electron

(2372kJ/mol), though it’s atomic radius is very small. ^>

Atomic Radius:

The distance from the nucleus to the shell. Francium has the largest atomic radius meaning it’s shell is the farthest from the nucleus. ^>

Electronegativity:

An atom's ability to attract electrons away from other atoms. The higher electronegativity means the more strongly that element attracts the shared electrons.^>

Electron Affinity:

The energy released when an atom gains an electron. The higher the electron affinity

an atom more easily accepts electrons. ^>

The 3 types of elements are Metals, Non-Metals, and Metalloids.

Metals:

Alkali Metals

  • Most reactive group of metals
  • Never found a combined element in nature
  • Soft/Shiny

Alkaline Earth Metals

  • 2nd most reactive group of metals
  • Shiny/Silvery white
  • Found in earth’s crust

Transitions

  • Largest group
  • High electron conductivity
  • Very hard, used for things like jewelry

Post-Transitions

  • Soft/Brittle
  • Poor conductors of electricity

Lanthanides

  • Known as rare-earth-metals

Actinides

  • Highly electropositive

Metalloids:

BORON DOWN (Al is not a metalloid)

  • Brittle, Hard
  • Somewhat reactive
  • Solids at room temperature

Non-Metals:

Halogens

  • Most reactive nonmetals
  • Salt-forming

Noble Gases

  • mostly non reactive
  • Colorless, orderless

Mendeleev arranged the 63 element by order of atomic mass ranked lightest to heaviest and published his draft in 1869. He predicted multiple different elements as well.

  • Never won any awards for his work

Valence Electrons: The amount of electrons on the outer shell, can also be predicted based on group of the element.

Ions: Positive or negative charge an element has depending on the number of electrons and protons. As an example Ca2+ = Carbon with 2 more protons than electrons. Cation ions are postive ions and Anion ions are negative ions.

Periodic functions: Trends/Patterns

Psychical Properties:

Luster

  • Ability to reflect light

Conductivity

  • An element ability to transmit or pass along heat/electricity

Malleability

  • Ability to bend before breaking

Ductility

  • Ability to pull into wire