Arranged by: Alex Peng
Periodic Table
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Period: 4
Elements in the same group have similar chemical properties, and will undergo
the same type of chemical reactions
As you move across a period, the properties of the elements will change
gradually from metallic to non-metallic
2.8.8.4
[2], [8], [8], [4]
Atomic number:
Number of Electrons:
22
1st Shell
Number of Protons:
4th Shell
[2+8+8+4]
Group number: IV
(remember to use
Roman Numerals)
Valence Electron: 4
Atomic Structure
Neutron
Proton (+)
Nucleon – found in the nucleus
(Overall positive charge)
Overall No charge
Nucleon (+) Electron (-)
Electron (-)
Mass number = Number of Neutron + Number of Proton = Nucleon Number
Atomic Number = Number of Protons/ Electrons
Number of Protons: 8
Atom Number of Electron: 8
Ion Number of Electron: 10
Atom Gain Electrons (-) Anion
Atom Lose Electrons (-) Cation
𝐈𝐨𝐧: 𝐎𝟐−
Full Electronic Configuration Diagram
e.g.
X
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Use pencil for Drawing
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Number of Protons and Neutrons in the Centre
Label the Contents
16 p
20 n
X
X
x= Electrons p= Protons n= Neutrons
Isotopes
Atoms that contain the same number of Protons and Electrons, but a different number
of Neutrons. Different physical properties
Atoms become Ions to obtain a full valence shell – A full valence shell is more stable
𝐈𝐨𝐧: 𝐎𝟐−
Charge of ion: -2
Ion has 2 more than Atom. (Atom -2)
=
(Ion) Number of Electrons gained: 2
Number of Electrons in the ion: 10
Number of Electrons in the Atom: 10-2 (8)
Lose Electrons (2-)
Positive ions (Ions has more than Atoms)
Gain Electrons- Negative Ions
Metals (Group I, II) usually form Cations (-)
Non-Metals (Group VII, 0) usually form Anions (+)
Chemical Bonding
Metal+ Non-Metal
Ionic Bond (Electrons Transferred)
Non Metal+ Non- MetalCovalent bond (Electrons Shared)
Aim:
Achieve Duplet/ Octet State
Full Valence Shell, more stable
Dot and Cross Diagram- Ionic Bonding (Ionic Structure)
*Note: Remember to write the Element Symbol in the Centre, and remember to draw the
Square Brackets outside.
*Note: Remember, its 2+ NOT +2!
Check for the number of Valence electrons in one element.
Find the Lowest common multiple. In this case, 2.
Calcium: 20 e/p Loses 2
Chlorine: 17 e/p Needs 1
Thus, CaCl2.
x2
Dot and Cross Diagram- Covalent Bonding
X= Carbon Electrons
= Hydrogen Electrons
= Nitrogen Electrons
X
Carbon
Hydrogen
X
X
XXX
Nitrogen
HCN
Carbon and Nitrogen has a Triple covalent bond - Three pair of shared electrons between
two atoms.
*Note: Look at the Valence Shell, not the Atomic Number.
E.g. Carbon. (6)
Electronic Configuration: 2.4
Valence Electron: 4. (NOT 2!)
Word Equations
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Metals go First. (E.g. Calcium Hydroxide)
Use Arrow; not equal Sign!