The Role of Ions and Ionization Energy in Chemistry

The video tutorial explains the concept of ions, which are atoms or molecules with a net charge due to an imbalance between protons and electrons. It distinguishes between positive ions (cations) and negative ions (anions), using examples like hydrogen and fluorine. The tutorial introduces ionization energy, the energy required to remove an electron, and discusses its trends across the periodic table. It highlights how ionization energy varies from low in alkali metals to high in noble gases, and how it changes as you move across and down the periodic table.

What is an ion?

• An atom or molecule with a charge due to unequal protons and electrons

• An atom with more neutrons than electrons

• An atom or molecule with a neutral charge

• A molecule with equal numbers of protons and neutrons

What is a cation?

• An ion with more electrons than protons

• A positive ion

• A neutral molecule

• A negative ion

Which of the following is an example of an anion?

• Lithium with one less electron

• Hydrogen with one less electron

• Fluorine with one extra electron

• Helium with an extra proton

What does ionization energy refer to?

• The energy required to add a proton

• The energy needed to add an electron

• The energy required to remove an electron

• The energy needed to balance protons and electrons

Why do alkali metals have low ionization energy?

• They easily lose an electron to achieve a noble gas configuration

• They have a full outer electron shell

• They have more protons than electrons

• They are very stable and do not lose electrons

What is the trend of ionization energy across a period from left to right?

• It fluctuates randomly

• It increases

• It remains constant

• It decreases

How does ionization energy change as you move down a group in the periodic table?

• It remains the same

• It increases

• It fluctuates

• It decreases

Which element would have a higher ionization energy, lithium or cesium?

• It depends on the temperature

• Both have the same ionization energy

• Cesium

• Lithium

Why do noble gases have high ionization energies?

• They have incomplete outer electron shells

• They are very reactive

• They have full outer electron shells and are stable

• They have more electrons than protons

What happens to ionization energy as atomic size increases?

• It becomes unpredictable

• It remains constant

• It decreases

• It increases