Question

1. most of the volume of an atom is occupied by the
2. atoms of the same element can differ in

matching

1. atoms with the same number of protons, but different numbers of neutrons in the nucleus of an atom
2. the total number of protons and neutrons in the nucleus of an atom
3. the number of protons in the nucleus of an element
4. the weighted average of the masses of the isotopes of an element
5. one-twelfth the mass of a carbon atom having six protons and six neutrons
6. an unknown element x has three naturally occurring isotopes:

x - 35: mass = 34.96885 amu, % abundance = 75.76%
x - 37: mass = 36.96590 amu, % abundance = 24.24%
x - 39: mass = 38.96371 amu, % abundance = 0.20%
a. calculate the average atomic mass of x. show all work for full credit.

b. identify the unknown element with name and atomic number:

Explanation:

Step1: Calculate the contribution of each isotope

For \(X - 35\):

$$34.96885\times0.7576 = 26.516$$

For \(X - 37\):

$$36.96590\times0.2424 = 8.9688$$

For \(X - 38\):

$$38.96371\times0.0020 = 0.0779$$

Step2: Sum up the contributions

$$26.516+8.9688 + 0.0779=35.5627\approx35.56$$

Chlorine (\(Cl\)) has an average atomic mass of approximately \(35.45\) amu (close to our calculated value of \(35.56\) amu considering rounding differences in the problem - given data). The atomic number of chlorine is \(17\).

Answer:

The average atomic mass of \(X\) is \(35.56\) amu.