Asked in Chemistry
What are the group 7 elements known as?
March 26, 2010 1:10PM
In the 'older' versions of the Periodic table this group 7 was known as the halogens (F, Cl, Br, I, At )
But later one decided that this group of halogens should be numbered as 17 in stead of 7.
This was done because the so called 'transition' elements (ten elements in each of the periods 4 till 7) have been put in between the groups 2 and 'old' 3.
So the original question: "What are the group 7 elements known as?" now has the answer:
In group 7 are the elements : Mn (25), Tc (43) and Re (75) and Uns (107) nowadays.