1. atomic structure and the periodic table

• Ions are atoms that have gained or lost one or more electrons.
• Cations are positively charged ions, while anions are negatively charged ions.
• Metals tend to lose electrons to form positive ions (cations), while non-metals gain electrons to form negative ions (anions).
• Rf​=Distance Travelled by Mobile Phase /Distance Travelled by Purple Spot​
• how do you calculate hr Rf value 


  Distance Travelled by Mobile Phase / Distance Travelled by Purple Spot ​