1st Quarter Reviewer for Physical Science

What is the estimated age of the universe according to detailed measurements of its expansion rate?

• 14.5 billion years
• 13.8 billion years
• 10 billion years
• 15.2 billion years

Which of the following describes alchemy?

• A modern scientific discipline
• A philosophical and spiritual field combined with chemistry.
• A branch of mathematics
• A form of astrology

Why is the period from 300,000 to 150 million years after the Big Bang referred to as the Dark Age?

• Due to the absence of cosmic microwave background radiation
• Because it marks the time when the universe was devoid of any matter
• The lack of star formation resulting in darkness
• Absence of any nuclear fusion reactions in stars

If a star is undergoing the process of nucleosynthesis, what is it primarily doing?

• Emitting light
• Fusing lighter elements to form heavier elements.
• Absorbing radiation
• Collapsing due to gravity

How does the concept of dark energy affect our understanding of the universe's expansion?

• It causes the universe to contract.
• It slows down the expansion rate of the universe.
• It accelerates the expansion rate of the universe.
• It has no effect on cosmic expansion.

Which term refers to the measure of the attraction of an atom for electrons in a covalent bond?

• Atomic radius
• Electronegativity
• Ionization energy
• Electron affinity

What is the term for a molecule with electron density distributed symmetrically?

• Polar molecule
• Nonpolar molecule
• Ionic molecule
• Dipole molecule

Why do polar and nonpolar substances not mix to form a solution?

• Due to their similar molecular structures
• Because of the repulsion between their charges
• Because of the alignment of partial charges
• Due to their differences in solubility

What determines the polarity of a molecule?

• The number of lone pairs
• The geometry of the molecule
• The difference in electronegativity
• The size of the atoms involved

How does electronegativity affect bond polarity?

• It determines the bond angle.
• It creates lone pairs.
• It influences the unequal sharing of electrons.
• It affects molecular geometry.