Hot Tips!! Elements in Periodic Table

·   Atoms that lose electrons (like metals) gain positive charge, becoming cations, such as Na+ or Mg²⁺.

·   Atoms that gain electrons (like non-metals) gain negative charge, becoming anions, such as Cl^– or O^2–

Elements tend to lose or gain as many electrons as necessary to have valence shells resembling the elements in Group VIIIA (noble gases):

• Group IA (alkali metal) elements lose one electron.
• Group IIA (alkaline earth metal) elements lose two electrons.
• Group VIIA (halogen) elements gain one electron.
• Group VIA elements tend to gain two electrons.
• Group VA elements tend to gain three electrons.

Sigma σ and Pi π bond

Different kinds of bonds result from the different ways the orbitals can overlap in space. The kind of symmetry the resulting bond has with the bond axis, (an imaginary line that connects the centers of the bonded atoms) determines what kind of bond is formed:

·   Sigma bond: When orbitals overlap in a way that is completely symmetrical with the bond axis, an σ bond (sigma bond) is formed. Sigma bonds form when s or p orbitals overlap in a head-on manner. Single bonds are usually sigma bonds.

·   Pi bond: When orbitals overlap in a way that is symmetrical with the bond axis in only one plane, a π bond (pi bond) is formed. Pi bonds form when adjacent p orbitals overlap above and below the bond axis.

Basic Knowledge about Bases

Bases:

·   Taste bitter (remember: test, not taste)

·   Feel slippery on the skin

·   React with oils and greases

·   React with litmus paper and turn it blue

·   React with acids to produce a salt and water

Basic Knowledge about Acid

Acid

·   Taste sour (remember: test, not taste)

·   Produce a painful sensation on the skin

·   React with certain metals (magnesium, zinc, and iron) to produce hydrogen (H₂) gas

·   React with limestone and baking soda to produce carbon dioxide

·   React with litmus paper and turn it red