In the mixture of table salt, sand, solid iodine and iron fillings, iron filings is the only solid that is magnetic. Hence, it can be separated using a magnet. When a magnet is moved through the mixture, iron fillings get attracted to the magnet out of the mixture, leaving the salt, iodine and sand.
JJ Thomson proved John Dalton's theory wrong, as Thomson discovered the electron. This showed that there were particles that were smaller than an atom, despite Dalton claiming that the atom is the smallest unit of matter.
The chain of colored boxes represent the first eight amino acids in the beta chain of hemoglobin. The sixth position in the normal beta chain has glutamic acid, while sickle beta chain has valine. This is the sole difference between the two
