The atomic mass of the element in period 2, group 13 of the periodic table of elements is 10.81. This group of chemical elements on the periodic table is called boron. In this group you can also find aluminum, galium, thallium, nihonium, and indium. Triels is another common name that refers to this group of elements.
These all have metallic properties with boron being a metalloid while the rest of them are post transition metals. Boron is not something found very often while others such as aluminum are very commonly found.