Explain why a graph of ionization energy versus atomic num ber (across a row) is not linear. Whe

Explain why a graph of ionization energy versus atomic num...

Key Concepts

Electron Configuration and Subshell Effects

The electron configuration of an atom, particularly the filling of specific orbitals and subshells, can lead to anomalies in the trend of ionization energies. Certain configurations, such as half-filled or fully filled subshells, provide extra stability and result in exceptions to the general trend, causing deviations from a linear pattern as the atomic number increases.

Periodic Trends

Periodic trends, such as the increase of ionization energy across a period, are based on fundamental principles of atomic structure. However, these trends are modulated by atomic factors like electron interactions, orbital penetration, and electron-electron repulsions, which lead to non-linear variations and specific exceptions among elements.

Ionization Energy

Ionization energy is the energy required to remove an electron from an isolated gaseous atom or ion. It generally increases with an increase in atomic number due to the stronger attraction exerted by the nucleus on the electrons, but the trend is not perfectly linear over a period because of varying sublevel electron arrangements.

Effective Nuclear Charge and Shielding

Effective nuclear charge is the net positive charge experienced by an electron in an atom, taking into account the shielding provided by other electrons. As atomic number increases across a period, the effective nuclear charge felt by the valence electrons typically increases, but differences in electron shielding and penetration due to different orbital types result in non-linear increases in ionization energy.

Transcript

00:01 Now we're being asked why, when we look at a certain row in the periodic table, why isn't the ionization energy constant as it goes across? and what are the exceptions in the general trends? so first of all, the general trend, when you're looking at the periodic table, is that as you move from the left side to the right, the ionization energy will increase.

00:28 And as you move down the table, the ionization energy will decrease.

00:38 With these actual trends in mind, we're looking at what causes this? what makes the energies change as you move across the period table? what's causing this is that as we move from these elements that have higher ionization energies to the lower ionization energies.

01:02 So we'll start off here and just sort of move down.

01:08 It'll move down as it moves across the row and then jump back up and move down, cross, down, cross.

01:20 Now this is the general trend that we'd be seeing.

01:26 This is being caused because we have orbitals that are being filled.

01:31 Here we have the d block, we have p block, and as these are being filled, the atomic number is going up, but the electrons aren't having more space.

01:47 So they are feeling the higher, an increasing amount of attraction to the positively charged nucleus, but they don't have additional spacing from it.

01:59 The size of the orbital remains the same.

02:03 Now, this means that because they are experiencing a higher attraction to the positive nucleus, it takes more energy to dislodge one of these electrons and ionize the atom as a whole...

Please give Ace some feedback