Chapter 2, Problem 2.22E

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

Carbon A carbon atom has a mass number of 12 and an atomic number of 6. How many neutrons does it have?

Copper (Cu) has an atomic number of 29 and a mass number of 64. One copper atom, therefore, has how many protons? a.27 b.29 c.31 d.35

The isotope Si-28 has a mass of 27.977 amu. For ten grams of Si-28, calculate (a) the number of atoms. (b) the total number of protons, neutrons, and electrons.

An isotope of americium (Am) with 146 neutrons is used in many smoke alarms. (a) How many electrons does an atom of americium have? (b) What is the isotope's mass number A? (c) Write its nuclear symbol.

Your friend tells you about an article that he read in a tabloid that reported the discovery of a new form of carbon containing eight protons in the nucleus of its atoms. He claims that scientists are eager to explore the properties of this new form of carbon. What is wrong with the tabloid's claim? a. Nothing. The claim is believable. b. The claim must be false because an atom with eight protons would be oxygen, which is already known. c. The claim must be false because all forms of carbon are already known.

2.12 Write the complete atomic symbol for each of the following isotopes. (a) carbon-13, (b) phosphorus-31, (c) sodium-23, (d) boron-10

A fundamental idea of Daltons atomic theory is that atoms of an element can be neither created nor destroyed. We now know that this is not always true. Specifically, it is not true for uranium and lead atoms as they appear in nature. Are the numbers of these atoms increasing or decreasing? Explain.

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?