Unit 2

On the basis of electronegativity differences between atoms, which of the following scientific claims is the most accurate regarding the bonding in Mg(NO₃)₂(s)?

• There is polar covalent bonding between Mg atoms and N atoms.

• There is polar covalent bonding between Mg atoms and O atoms.

• There is ionic bonding between N⁵⁺ ions and O²⁻ ions.

• There is ionic bonding between Mg²⁺ ions and NO₃⁻ ions.

Which of the following claims about a binary compound in which the bonding is ionic is most likely to be scientifically valid?

• Both elements in the compound are metals.

• The atomic masses of the elements in the compound are relatively small.

• There is equal sharing of electrons between the atoms of the elements in the compound.

• The electronegativity difference between the elements in the compound is relatively large.

Which of the following claims about a binary compound composed of elements with the same electronegativity is most likely to be true?

• The compound has properties similar to those of both elements.

• The bonding in the compound is nonpolar covalent.

• The boiling point of the compound is above 1000°C

• The compound contains strong ionic bonds.

Molten (liquid) NaCl is represented by the particulate diagram shown above. Which of the following indicates whether NaCl(l) conducts electricity and best explains why or why not?

• It conducts electricity because Na is a metal.

• It conducts electricity because ions are free to move.

• It does not conduct electricity because Cl is a nonmetal.

• It does not conduct electricity because there are no free electrons.

The particulate-level diagram shown above best helps to explain which of the following properties of ionic solids?

• density

• brittleness

• malleability

• conductivity

Tags

NGSS.HS-PS1-1

The particles in solid KI, a stable ionic compound, are arranged to maximize coulombic attractions while minimizing coulombic repulsions among the particles. Which of the following diagrams best represents the structure of solid KI?

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Which of the following indicates whether the solid substance represented by the particulate diagram shown above conducts electricity and explains why or why not?

• It conducts electricity because it is made of positive and negative particles.

• It conducts electricity because electrons are free to move through the substance.

• It does not conduct electricity because electrons are strongly attracted to specific positive particles.

• It does not conduct electricity because the positive particles are not free to move through the substance.

Tags

NGSS.HS-PS1-3

NGSS.HS-PS2-6

Which of the following is an interstitial alloy?

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Tags

NGSS.HS-PS1-3

The diagram above best illustrates which of the following phenomena associated with solids that have metallic bonding?

• Electrical conductivity, because it shows a lattice of positive ions immersed in a sea of electrons.

• Malleability, because it shows how adjacent layers of positive ions can move relative to one another while remaining in full contact with the electron sea.

• Heat conductivity, because it shows how layers of atoms can slide past one another, creating friction between layers and causing the temperature of the solid to increase.

• The ability to form substitutional alloys, because it shows how atoms of two different metals can combine in a one-to-one ratio.