Francium is often ignored because it is the second rarest element on the planet. Only about 30 grams of it exist in Earth's crust at any given time. Nobody has been able to have more than a few thousand francium atoms in one place.
Francium is also has a very short half-life, 22 minutes. Meaning that if you have a sample of francium half of it will have decayed into other elements after 22 minutes.
The chemistry of francium is not known.
The chemistry of francium is practically unknown.
The chemistry of francium is not known; francium has properties similar to caesium.
The chemistry of francium is practically unknown.
The chemistry of francium is practically unknown.
The chemistry of francium is practically unknown.
The chemistry of francium is not known but it is supposed that francium can react with the majority of nonmetals.
The chemistry of francium is not known but it is supposed that francium can react with the majority of nonmetals.
The chemistry of francium is practically unknown today.
The chemistry of francium is practically unknown.
The chemistry of francium is not experimentally known; it is only estimated.
The chemistry of francium is not known; it is probable that francium easy react with nonmetals.