CLEP Chemistry Free Sample Questions

Gallium has two naturally occurring stable isotopes: Ga-69 with an isotopic mass of 68.926 amu and Ga-71 with an isotopic mass of 70.925 amu. Given that the standard atomic weight of gallium reported on the periodic table is 69.723 amu, what is the natural percent abundance of the Ga-69 isotope?

The successive molar ionization energies for an unknown representative element in Period 3 are determined experimentally as follows:

• First ionization energy (IE1): 738 kJ/mol
• Second ionization energy (IE2): 1,451 kJ/mol
• Third ionization energy (IE3): 7,733 kJ/mol
• Fourth ionization energy (IE4): 10,543 kJ/mol

Based on these ionization energy values, which element is being evaluated?

In the radioactive decay series of uranium-238, a thorium-234 nucleus undergoes beta-minus (β⁻) emission to form an excited daughter nucleus of _____.

According to valence shell electron pair repulsion (VSEPR) theory, what is the molecular geometry and the orbital hybridization of the central sulfur atom in sulfur tetrafluoride (SF4)?

Consider the bonding and molecular structure of acrylonitrile, H2C=CH-C≡N. Which TWO of the following statements correctly describe the covalent bonds and orbital hybridization in this molecule? (Select TWO)

True or False: Network covalent solids, such as silicon dioxide (SiO2) and diamond (C), exhibit substantially higher melting points than molecular solids, such as sucrose (C12H22O11) and dry ice (CO2), because melting network solids requires rupturing strong covalent bonds throughout the entire macroscopic lattice rather than disrupting relatively weak intermolecular forces.