An unknown element, X, occurs naturally as three isotopes. …

An unknown element, X, occurs naturally as three isotopes.  In a sample of this element, 28X has a mass of 27.977 amu and is 92.21% abundant in the sample, 29X  has a mass of 28.976 amu  and is 4.70% abundant in the sample and 30X has a mass of 29.974 amu  and is 3.09% abundant in the sample (1) Calculate the Average Atomic Mass (weighted average) of this element.  Report to proper number of significant figures and units.   SHOW WORK FOR IN ORDER TO EARN FULL CREDIT. HINT:  Set up a table like shown in the notes. (2)  What is the identity of this element?  HINT:  Use the average atomic mass and reference the Periodic Table.