A mystery element’s mass spectrum shows it to be 13.92 % Isotope A (219 amu), 72.16 % Isotope B (222 amu), and 13.92 % Isotope C (225 amu).
a. What is the atomic weight of the element?

b. What is the element?

The given element is Radon because its atomic weight is 222 amu.

Explanation:

Given data:

Percentage of A-219 = 13.92%

Percentage of B-222 = 72.16%

Percentage of C-225 = 13.92%

Atomic weight of element = ?

Solution:

Average atomic mass = (abundance of A isotope × its atomic mass) +(abundance of B isotope × its atomic mass) + (abundance of C isotope × its atomic mass)  / 100

Average atomic mass  = (13.92×219)+(72.16×222) + (13.92×225)/100

Average atomic mass =  3048.48 + 16019.52 +3132/ 100

Average atomic mass  = 22200 / 100

Average atomic mass  = 222 amu.

The given element is Radon because its atomic weight is 222 amu.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

the product of the pressure and volume is also constant