How are electrons ‘arranged’ in an atom?

(& how do we know this)

1) Describe the nature of the interaction between protons and electrons in an atom? Use as many of the following terms in your description as you can:

attraction

repulsion

neutral

positive

negative

charge

distance

nucleus

force

energy

Coulomb’s Law.

2a) Define ionization energy:

b) Based on the definition above what charge will the atom have now?

3) Explain what happens to the repulsion between the remaining electrons when an electron is removed.

4) Summarize Coulomb’s Law & the interaction between magnets activity.

5) How does the force between two opposite charges affect the energy required to separate them?

6) Model 1: What energy to remove an electron tells us about distance.

In the model below single proton is shown. Use the data to the right to determine the relative locations of a single electron in each model. Draw these electrons in the locations you predict.

Energy (kiloJoules/mole)

a) 500

b) 1000

c) 1500

d) Give reasons for the location of your electrons in Model 1.

7) Model 2: What energy to remove an electron tells us about total nuclear charge.

In the model below a single electron is shown. Use the data to the right to determine the relative number of protons present in the nucleus. Draw these protons in the circles provided.

Energy (kiloJoules/mole)

a) 500

b) 1000

c) 1500

d) Give reasons for the number of protons in Model 2.

8. The values for the first ionization energy for a hydrogen and helium atom are provided in the table below.

Atom / H / He / Li
Ionization Energy (kJ mol-1) / 1312 / 2373

a) Based on Models 1 & 2 how would you explain the difference in the values for the first ionization energy for hydrogen and helium?

b) How does your explanation account for the relative charge on hydrogen and helium and the distance of the electron(s) from the nucleus.

c) Predict a value for the first ionization energy for lithium. Justify.

d) The value of the ionization energy of lithium is ______kJ mol-1. Based on Models 1 & 2, how would you explain the ionization energy for lithium compared to the ionization energy for helium? Compared to hydrogen?

9) What trend in energy of ionization do you notice as you move down the periodic table? Explain the reason for this trend.

10) The first ionization energies for selected elements from the second period of the periodic table follows;

Atom / 3Li / 4Be / 6C / 7N / 9F / 10Ne
Ionization Energy (kJ mol-1) / 520 / 899 / 1086 / 1302 / 1681 / 2081

Explain the trend in ionization energies in terms of the relative location of the electrons and the charge of the nucleus.

11) What trend in ionization energy do you notice in the periodic table as you move across the table, left to right? Explain the reason for this trend.

Synthesis: Bringing it all together to make a prediction.

12) The first ionization energy for the element sodium is given in the following table. Predict the other values for the selected third period elements;

Atom / 11Na / 12Mg / 14Si / 15P / 17Cl / 18Ar
Ionization Energy (kJ mol-1) / 495

How did you arrive at your predictions?

11) Describe the electron structure (location of the electron) of the atom. Consider using some or all of the following terms in your description; nucleus, electron, energy, distance, level, proton, shell, arrangement, attraction, repulsion, positive, negative, charge, location.