Thursday 17 January 2013

#6 Entry- Atomic Structure

Today we covered Atomic Structure.

So, and element can be split into many sub-groups.
Element-->atom --> sub-atomic particle (number of particles, periodic table)
Element--> Made up by molecule

So what is sub-atomic particle?
Basically, they are the smaller parts that make up the atoms. They consists of protons, neutrons and electrons.

Protons and Neutrons are called nucleons and they are found in the nucleus.

Relative Mass
Since an atom's mass is almost negligible, scientists have came up with a simpler, more generalised form of its mass. It is termed 'Relative Mass'.

Relative Mass is represented by 'amu'. So 1 amu= 1.67x 10^-27 kg

Proton

  • Carries a charge of +1
  • Has a relative mass of 1
  • Symbol = p


Neutron

  • It has no charge
  • Comes from the word 'neutral'
  • Relative mass of 1
  • Makes an atom radioactive 
  • Symbol = n

Electron

  • Carries a charge of -1
  • Negligible mass/ relative mass of 1/1840
  • Found in shells, surrounding the atom
  • Symbol = e
General Information of Atoms

  • All atoms are electrically neutral
  • Equal number of charges
How to read the elements on a Periodic Table

  • Proton number = z
  • Atomic Number (number in superscript)
  • Nucleon number (A) = Proton + neutron 
  • Each element has a unique proton number
  • Nucleon number: Proton + neutron
  • Every element has a unique proton number
  • Mass number and Nucleon number share the same number, but they are not the same thing
(Reason: Take for example Carbon, which nucleon number is 6, and proton number is 6. So it has 6 protons, and 6 neutrons:
6p = 1 x 6
6n = 1 x 6
The total number is 12, which is the same as the nucleon number. )


Above shows how to read an element on a periodic table.


Reflection: Today we learnt something new: Sub-atomic number. It was quite interesting since I once thought cells were the smallest unit of life on Earth then I learnt that there were molecules and then there were atoms and now, sub-atomic particles! Interesting it is, how small things can get!


Next lesson: Separation techniques

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