Q3 Reviewer PhySci

Identify the element that was NOT formed during this early stage of the universe.

• Hydrogen

• Helium

• Lithium

• Carbon

Understanding atomic numbers was crucial for synthesizing new elements. Atomic number is defined as the number of:

• protons in the nucleus.

• neutrons in the nucleus.

• electrons in the outermost shell.

• total number of protons and neutrons.

The key factor that Moseley used to reorganize the periodic table, led to a better understanding of elemental properties was:

• atomic mass.

• atomic radius.

• atomic number.

• number of neutrons.

Which group of elements typically has 8 valence electrons, making them very stable?

• Halogens

• Noble gases

• Alkali metals

• Alkaline earth metals

What does Lewis dot structure represent?

• Core electrons

• Valence electrons

• Protons in the nucleus

• Neutrons in the nucleus

Which molecular shape is MOST LIKELY to result in a nonpolar molecule, assuming the surrounding atoms are identical?

• Bent

• Square Pyramidal

• Tetrahedral

• Trigonal pyramidal

The presence of lone pairs on the central atom of a molecule generally leads to what?

• A polar molecule

• A nonpolar molecule

• No change in polarity

• An increase in symmetry

What intermolecular forces is STRONGEST in polar molecules?

• Hydrogen bonding

• Van der Waals forces

• London dispersion forces

• Dipole-dipole interactions

What intermolecular force is present in ALL molecules, even nonpolar ones?

• Hydrogen bonding

• Ionic interactions

• London dispersion forces

• Dipole-dipole interactions

They influence various physical properties of substances. Which intermolecular force is the weakest?

• Hydrogen bonding

• Ionic interactions

• Dipole-dipole interactions

• London dispersion forces