An unidentified element is found to have an electron configuration by shell of 2 8 18 8 2. To what group and period does this element belong? Is the element a metal or a nonmetal? How many protons does an atom of the element have? What is the name of the element? Write its electron-dot symbol.

Verified step by step guidance

1. Identify the electron configuration by shell: 2, 8, 18, 8, 2.
2. Determine the period by counting the number of shells. The element has 5 shells, so it is in period 5.
3. Determine the group by looking at the number of electrons in the outermost shell. The outermost shell has 2 electrons, indicating it is in group 2.
4. Since the element is in group 2, it is an alkaline earth metal.
5. Calculate the atomic number by summing the electrons: 2 + 8 + 18 + 8 + 2 = 40. The element with atomic number 40 is Zirconium (Zr). Its electron-dot symbol is 'Zr' with no dots, as it typically does not form simple covalent bonds.

Key Concepts

Electron Configuration

Electron configuration describes the distribution of electrons in an atom's electron shells and subshells. The notation '2 8 18 8 2' indicates the number of electrons in each shell, which helps determine the element's position in the periodic table. Understanding electron configuration is crucial for identifying an element's group, period, and chemical properties.

Periodic Table Organization

The periodic table organizes elements based on their atomic number and electron configuration. Elements are arranged in rows called periods and columns known as groups. The group number indicates the number of valence electrons, which influences whether an element behaves as a metal or nonmetal, and helps predict its chemical reactivity.

Valence Electrons and Chemical Properties

Valence electrons are the outermost electrons in an atom and play a key role in determining an element's chemical behavior. Metals typically have fewer valence electrons and tend to lose them, while nonmetals have more and tend to gain or share them. The number of valence electrons can be inferred from the group number, aiding in identifying the element's classification as a metal or nonmetal.