Use the periodic table and predict the number of electrons that will be lost or gained by the following elements as they change into simple ions. Write an equation using elemental symbols, ionic symbols, and electrons to represent each change.
a) Ca
b) Aluminum
c) Fluorine
d) Element number 34
What exactly is your problem in doing this?
To predict the number of electrons that will be lost or gained by an element as it changes into a simple ion, we need to know the element's position on the periodic table.
a) Calcium (Ca) is located in Group 2 of the periodic table. Elements in Group 2, also known as the alkaline earth metals, tend to lose 2 electrons to form stable ions. Therefore, the equation for the change of calcium into a simple ion can be represented as:
Ca → Ca^2+ + 2e^-
b) Aluminum is located in Group 3 of the periodic table, also known as the boron group. Elements in this group often lose 3 electrons to achieve stability. Hence, the equation for the change of aluminum into a simple ion can be represented as:
Al → Al^3+ + 3e^-
c) Fluorine (F) is located in Group 17 of the periodic table, also known as the halogens. Elements in this group typically gain 1 electron to achieve stability. Therefore, the equation for the change of fluorine into a simple ion can be represented as:
F + e^- → F^-
d) Element number 34 refers to Selenium (Se), which is found in Group 16 of the periodic table, also called the chalcogens. Elements in this group usually gain 2 electrons to achieve stability. Thus, the equation for the change of selenium into a simple ion can be represented as:
Se + 2e^- → Se^2-
Remember that when an element loses electrons, it forms a positively charged ion (cation), indicated by a superscripted "+". On the other hand, when an element gains electrons, it forms a negatively charged ion (anion), indicated by a superscripted "-". The number of electrons gained or lost can be determined by the element's group number on the periodic table.