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Science · Drill 42

Science practice 42

11 questions ~9 min recommended
⏱ 00:00
Score
—

Electron (-)
Protons
(+)

X + Ionization energy → X+ + Electron

X+2 + Ionization Energy → Xt + electron

Atom H He Li Be N F Ne
Protons 1 2 3 4 5 6 7 8 9 10
First 1,312 2,372 5201 900 801 1,087 1,402 1,314 1,681 2,081
Second 5,250 7,298 1,757 2,427 2,353 2,856 3,388 3,374 3,952
Third 11,815 14,8492 3,659 4,621 4,578 5,300 6,050 6,122
Fourth 21,007 25,025 6,223 7,475 7,469 8,408 9,371
Fifth 32,827 37,831 9,445 10,990 11,023 12,177
Sixth 47,277 53,267 13,327 15,164 15,238
Seventh 64,360 71,330 17,868 19,999
Eighth
Ninth
Tenth 84,078 92,038 23,070 106,434 115,380 131,432

In 1922, Niels Bohr revised the atomic model to include a positively charged nucleus surrounded by negatively charged electrons that traveled in well-defined shells around the nucleus. The shells can be thought of as concentric circles around the nucleus. A neutral atom contains the same number of protons in the nucleus as electrons surrounding the nucleus. The inside shell can hold two electrons, and the second shell can hold eight electrons. An electrostatic attraction occurs between the positively charged protons in the nucleus and the negatively charged electrons. A representation of Bohr's shell model is shown in Figure 12.1.

Figure 12.1

Partial evidence for this atomic shell model comes from the study of ionization energies of different elements. Ionization energy is the amount of energy required to remove an electron from an atom or ion in the gaseous state. The first ionization energy removes the electron farthest from the nucleus and can be represented by the following formula:

where X represents a neutral atom.

The nth ionization energy removes additional electrons from an already charged ion. For example, the third ionization energy can be represented by the following formula:

The ionization energies in kJ/mol of the first 10 elements can be found in Table 12.1.

TABLE 12.1

1. How much energy does it take to remove the outermost electron from beryllium (Be)?

2. Which of the following statements regarding the ionization energy of the third proton of the elements listed is true?

3. How much energy is required to remove an electron from nitrogen as shown in the following equation?

4. The first ionization energy of Element 2, hydrogen, is much larger than the first ionization energy for Element 3, lithium. Which statement best explains this trend?

5. Which best explains why there is no seventh ionization energy listed for the element carbon?

6. Figure 12.2 shows an electron being removed from the element oxygen. How much energy is associated with the image shown?


Figure 12.2

7. According to Table 12.1, how many electrons must the element nitrogen have in its outermost shell?

8. Referring to Table 12.1, what evidence supports the fact that each element has only two electrons in the first, innermost shell?

9. Which set of ionization energy (IE) data represents an atom that has one electron in its outermost electron shell?

First IE, Second IE, Third IE, Fourth IE

10. Helium and lithium are isoelectronic. This means their electron structure is identical. They both have two electrons in the first shell outside of the nucleus. Why does it take less energy to remove an electron from helium than it does to remove an electron from lithium?

11. How many kJ of energy would be required to remove all of the electrons from 1 mol of helium atoms?

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