An element has two naturally occurring isotopes, x-85 with a mass of 84.9118 amu and a natural abundance of 72.17%, and x-87 with a mass of 86.9092 amu and a natural abundance of 27.83%. calculate the atomic mass of this element.

This element is Rubidium (Rb) and has an average atomic mass of 85.468 u

Explanation:

The average mass of an element is calculated by taking the average of the atomic masses of its stable isotopes.

The enitre atomic mass = 100 % or 1

⇒ this consists of X-85 with 72.17 % abundance  with atomic massof  84.9118 g/mol

72.17 % = 0.7217

⇒ this consists of X-87 with  27.83 % abundance with atomic mass of 86.9092 g/mol

27.83 % = 0.2783

To calculate the mass of this isotope we use the following:

0.7271 * 84.9118 + 0.2783 * 86.9092 =85.468 g/mol

This element is Rubidium(Rb) and has an average atomic mass of 85.468 u

answer: they produce more slow than unicellular organisms.

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them