3. Which of the following atoms are isotopes of the same element? Identify the elements of these isotopes and describe the number of protons and neutrons in the nucleus of them all. 17 15 7 X 12 13 18 14 14 16 13 EX 7 X 8 X 7 X 6 X 8 X 6 X 8 X

The following table gives the number of protons and neutrons in the nuclei of various atoms. Which atom is the isotope of atom A? Which atom has the same mass number as atom A? Protons Neutrons Atom A 32 39 Atom B 33 38 Atom C 38 50 Atom D 32 38

Xenon An isotope of xenon has an atomic number of 54 and contains 77 neutrons. What is the xenon isotope’s mass number?

In what way are isotopes of a given element always different? In what way(s) are they always the same?

Give the atomic number (Z) and the mass number (A) for each of the following: a. a carbon atom with 8 neutrons b. an aluminum atom with 14 neutrons c. an argon atom with 20 neutrons d. a copper atom with 36 neutrons

2.90 Naturally occurring europium has an average atomic weight of 151.964 amu. If the only isotopes of europium present are 151Eu and 153Eu, describe how you would determine the relative abundance of the two isotopes. Include in your description any information that would need to be looked up.

What are the different kinds of particles in the atoms nucleus? Compare their properties with each other and with those of an electron.