Question

select the correct statement(s).
hydrogen (h) and lithium (li) are in the same period on
the periodic table and have one valence electron.
hydrogen and lithium are in different groups on the
periodic table and have different numbers of total
electrons.
hydrogen (h) and lithium (li) are in different periods on
the periodic table and have different numbers of
electron shells or energy levels.
hydrogen (h) and lithium (li) are in the same group on
the periodic table and have different atomic numbers
and masses.
hydrogen (h) and lithium (li) are in different periods on
the periodic table and have the same number of
electron shells or energy levels.
hydrogen (h) and lithium (li) are in the same group on
the periodic table and have one valence electron

Explanation:

• Group and Period Concepts:
• Group: Elements in the same group have the same number of valence electrons. Hydrogen (\(H\)) and lithium (\(Li\)) have 1 valence electron each, so they are in the same group (Group 1).
• Period: A period number indicates the number of electron shells. Hydrogen (\(H\)) is in Period 1 (1 electron shell), and lithium (\(Li\)) is in Period 2 (2 electron shells).
• Atomic Number and Mass: Atomic number of \(H = 1\), \(Li=3\). Mass of \(H\approx1u\), \(Li\approx7u\).
• Analysis of Statements:
• First Statement: \(H\) (Period 1) and \(Li\) (Period 2) are not in the same period. So, this statement is incorrect.
• Second Statement: \(H\) and \(Li\) are in the same group (Group 1). So, this statement is incorrect.
• Third Statement: \(H\) (Period 1, 1 shell) and \(Li\) (Period 2, 2 shells) are in different periods and have different numbers of shells. This statement is correct.
• Fourth Statement: \(H\) and \(Li\) are in the same group (Group 1), and they have different atomic numbers (\(H = 1\), \(Li = 3\)) and masses (\(H\approx1u\), \(Li\approx7u\)). This statement is correct.
• Fifth Statement: \(H\) (1 shell) and \(Li\) (2 shells) do not have the same number of shells. So, this statement is incorrect.
• Sixth Statement: \(H\) and \(Li\) are in the same group (Group 1) and have 1 valence electron each. This statement is correct.

Answer:

Hydrogen (\(H\)) and lithium (\(Li\)) are in different periods on the periodic table and have different numbers of electron shells or energy levels. ; Hydrogen (\(H\)) and lithium (\(Li\)) are in the same group on the periodic table and have different atomic numbers and masses. ; Hydrogen (\(H\)) and lithium (\(Li\)) are in the same group on the periodic table and have one valence electron.