Final answer:
The element from Group IA of the periodic table that has a mass of 7.675 grams for 2.01 × 1023 atoms is most likely sodium (Na), as the calculated molar mass is closest to the known molar mass of Na (approximately 22.99 g/mol).
Step-by-step explanation:
If 2.01 × 1023 atoms of an element from Group IA of the periodic table have a mass of 7.675 grams, we can determine which element this is by using the concept of molar mass. The Group IA elements, also known as the alkali metals, include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs). The number of atoms given is approximately one-third of Avogadro's number (6.02 × 1023), which corresponds to one-third of a mole.
For each element:
Lithium (Li) has a molar mass of about 6.94 g/mol.
Sodium (Na) has a molar mass of about 22.99 g/mol.
Potassium (K) has a molar mass of about 39.1 g/mol.
Rubidium (Rb) has a molar mass of about 85.47 g/mol.
Cesium (Cs) has a molar mass of about 132.9 g/mol.
To find the approximate molar mass of our sample, we can multiply the given mass by 3 (since we have one-third of a mole), resulting in a molar mass of about 23 g/mol. Looking at the molar masses of the Group IA elements, sodium (Na) is the closest to this value. Thus, the element is most likely sodium (Na).