SPM Chemistry Form 4 Notes – Periodic Table of Elements (Part 5)

by BerryBerryTeacher

in Berry Reference (Notes)

What is the trends of elements across a period? This is one of the most often asked question in chemistry examinations (or pop quizzes). As SPM students are required to know their periodic table of elements very well, recognising trends of elements across a period is of utmost importance. For this Part 5 of Berry Berry Easy notes on SPM Chemsitry Form 4 – Periodic Table of Elements, the changes across period 3 is discussed in detail. Atomic radius, proton number, electronegativity, phase changes and other changes will be explained in point form for easy reading. Students are advised to read the previous 4 parts in the series of notes before proceeding to this post, in order to better understand this part.

(Tips: You should draw out the entire Period 3 and then draw the elements based on their size, colour, electronegativity (use size of negative signs to represent the levels), the phase which is appears in (s = solid, g = gas, l = liquid) and all other characteristics. Then paste this figure that you have drawn on your desktop. This way you’ll see it until you have it in the back of your head.)

SPM Chemistry Form 4 Notes – Periodic Table of Elements (Part 5)

 

Elements: Zinc Copper Lead Magnesium

Elements: Zinc Copper Lead Magnesium

 

Elements in a period

  • The Periodic Table – 7 periods (Period 1 to Period 7)
  • Proton number increases by one (across a period – from left to right)
  • Number of valence electrons of each element increases (across a period – from left to right)

Across Period 3

  • Atomic radius / atomic size decreases – increasing number of electrons / attraction by nucleus on the valence electrons becomes stronger (pulled closer to the nucleus)
  • Proton number increases – positive charge of the nucleus increases
  • Electronegativity (strength to attract electrons towards its nucleus) increases – proton number increases / positive charge of the nucleus increases
  • Change from solid to gas
  • Left – solid metals
  • Right – non-metals gases
  • Electropositive / metallic properties decreases
  • Na, Mg, Al (metals): good conductor / Si (semi-metal): weak conductor of electricity / P, S, Cl (non-metals): cannot conduct electricity
  • Na, Mg (metals): form oxides with basic properties
  • Al (metal): form oxides with both basic and acidic properties = amphoteric oxides
  • Si (semi-metal): forms oxides with acidic properties
  • P, S, Cl (non-metals): forms oxides with acidic properties

Uses of semi-metals (metalloids)

  • Semiconductor (flow in one direction)
  • Microchip

The next part, Part 5 is the final part in this series of notes from Berry Berry Easy on the Periodic Table of Elements for SPM Chemistry Form 4 students. The next post which conclude the entire series of post will be on transition elements.

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October 22, 2011
October 23, 2011

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