A. What is the group number and name of the group that...

a. What is the group number and name of the group that contains potassium? b. Is potassium a metal, a nonmetal, or a metalloid? c. How many protons are in an atom of potassium? d. What is the most prevalent isotope of potassium (see Table $4.8)$ ? e. Potassium has three naturally occurring isotopes. They are $\mathrm{K}-39(93.26 \%, 38.964 \mathrm{amu}), \mathrm{K}-40(0.0117 \%, 39.964 \mathrm{amu})$ and $\mathrm{K}-41(6.73 \%, 40.962 \mathrm{amu}) .$ Calculate the atomic mass of potassium from the naturally occurring isotopes and their abundance using the weighted average mass method.

a. What is the group number and name of the group that contains potassium?
b. Is potassium a metal, a nonmetal, or a metalloid?
c. How many protons are in an atom of potassium?
d. What is the most prevalent isotope of potassium (see Table $4.8)$ ?
e. Potassium has three naturally occurring isotopes. They are $\mathrm{K}-39(93.26 \%, 38.964 \mathrm{amu}), \mathrm{K}-40(0.0117 \%, 39.964 \mathrm{amu})$ and $\mathrm{K}-41(6.73 \%, 40.962 \mathrm{amu}) .$ Calculate the atomic mass of potassium from the naturally occurring isotopes and their abundance using the weighted average mass method.

Key Concepts

Weighted Average Atomic Mass Calculation

The atomic mass listed on the periodic table is a weighted average that takes into account the mass of each isotope and its relative abundance. This calculation involves multiplying the mass of each isotope by its percentage (expressed as a fraction), then summing the resulting values to yield the overall atomic mass of the element.

Isotopes and Isotopic Abundance

Isotopes of an element have the same number of protons but differ in the number of neutrons, resulting in different atomic masses. Natural elements typically have a mixture of isotopes, and the relative abundance of these isotopes affects the calculated average atomic mass of the element.

Periodic Table Groups

Elements in the periodic table are organized in vertical columns known as groups. Each group contains elements that have similar chemical properties due to their similar electron configurations. For instance, the group containing potassium belongs to the alkali metals, which are known for their high reactivity and single valence electron.

Element Classification (Metals, Nonmetals, and Metalloids)

Elements are classified based on their typical physical and chemical properties into metals, nonmetals, and metalloids. Metals generally exhibit properties such as high electrical conductivity, malleability, and luster. Recognizing whether an element is a metal helps in understanding its physical characteristics and reactivities.

Atomic Structure - Protons

An atom's identity is determined by the number of protons in its nucleus, known as the atomic number. This concept is fundamental in atomic theory and is crucial for determining the element's position on the periodic table, influencing its chemical behavior and properties.