Chapter 2, Problem 2.12E

What particles are found in the nucleus of an atom? What is the charge of the nucleus?

2.11 Define the term isotope.

Write isotope symbols for neutral atoms with the following characteristics: a. Contains 20 electrons and 20 neutrons b. Contains 1 electron and 2 neutrons c. A magnesium atom that contains 14 neutrons

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

Scientists J. J. Thomson and William Thomson (Lord Kelvin) made numerous contributions to our understanding of the atom’s structure. Which subatomic particle did J. J. Thomson discover, and what did this lead him to postulate about the nature of the atom? William Thomson postulated what became known as the “plum pudding” model of the atom’s structure. What did this model suggest?

Atoms are electrically neutral. This means that an atom will contain a.more protons than neutrons. b.more electrons than protons. c.an equal number of protons and electrons. d.None of the above.

Compounds of europium. Eu, are used to make color television screens. The europium nucleus has a charge of +63. How many electrons are there in the neutral atom? in the Eu3+ ion?

A student in your chemistry class tells you that nitrogen-14 and nitrogen-15 are not isotopes because they have the same number of protons. How would you refute this statement?

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