Unit 1: Water - Particle Theory, Atomic Structure, Chemical Bonding, and Properties

Flashcards covering particle theory of matter, atomic structure, covalent and ionic bonding, salts, hydrogen bonding, and the physical and chemical properties of water.

How are water molecules arranged and how do they move in solid ice?

In solid ice, water molecules have a rigid lattice structure and vibrate in place.

How are water molecules arranged and how do they move in liquid water?

Liquid water molecules have an irregular arrangement and slide past each other in a sliding motion, taking on the shape of their container.

How do water molecules arrange and move in the gas phase?

In the gas phase, water molecules have an irregular arrangement, bounce off each other, and fill the entire volume of their container.

How do kinetic energy and molecular speed change during phase transitions between solid, liquid, and gas water?

Water molecules gain kinetic energy and move faster when transitioning from liquid to gas, whereas they lose kinetic energy and move slower when transitioning from liquid to solid.

In a neutrally-charged atom, what is the relationship between the number of protons and electrons?

The number of protons equals the number of electrons ($\text{protons} = \text{electrons}$).

How many electrons are required to fill the first, second, and third electron shells for maximum stability?

The first shell closest to the nucleus holds 2 electrons, while the second and third shells hold 8 electrons each.

What are the locations, charges, and relative masses of protons, neutrons, and electrons in an atom?

Protons are in the nucleus with a positive charge and a relative mass of 1; neutrons are in the nucleus with neutral/no charge and a relative mass of 1; electrons orbit the nucleus in shells with a negative charge and almost no mass.

Why is sea water classified as a mixture, and what are specific examples of its dissolved components?

Sea water is a mixture because water acts as the solvent dissolving various solutes, including salt ions (such as sodium ion and chloride ion), organic compounds (such as glucose), and dissolved gases (such as carbon dioxide and oxygen).

What type of chemical bonding occurs within a single water molecule, and how are the electrons arranged?

A covalent bond occurs within a single water molecule, where 2 hydrogen atoms share outer electrons with 1 oxygen atom to fill their outer electron shells.

How many valence electrons do hydrogen and oxygen possess, and how many are needed to fill their outer shells in a water molecule?

Hydrogen has 1 valence electron and needs 1 more to fill its shell, while oxygen has 6 valence electrons and needs 2 more to fill its outer shell.

Which five covalent molecules are highlighted for diagram identification in the notes?

Water, Oxygen, Carbon Dioxide, Glucose, and Sulfur Dioxide.

How does ionic bonding occur in the formation of sodium chloride?

A sodium atom loses 1 electron to become a positively charged sodium ion, while a chlorine atom gains 1 electron to become a negatively charged chloride ion; the opposite charges attract to form a lattice structure.

What are the chemical formulas for the salts sodium chloride, calcium carbonate, and magnesium sulfate?

Sodium chloride is $NaCl$, calcium carbonate is $CaCO_3$, and magnesium sulfate is $MgSO_4$.

What type of bonding occurs between multiple water molecules, and what causes it?

Hydrogen bonding occurs between multiple water molecules as a weak electrostatic attraction between the slightly/partially positive hydrogen of one molecule and the slightly/partially negative oxygen of another molecule.

Why is water considered a polar molecule in terms of nuclear charge?

Water is polar because the oxygen nucleus has a charge of +8 while the hydrogen nucleus has a charge of only +1, pulling the shared electrons more strongly toward the oxygen atom.

What feature of hydrogen bonding enables water's effective solvent action on ions?

The constant breaking and reforming of hydrogen bonds allows water molecules to easily surround and dissolve ionic solutes.

Why does ice have a lower density than liquid water and float?

Water expands when it freezes into a hexagonal lattice structure with the maximum number of hydrogen bonds, spacing the molecules further apart and making ice less dense than liquid water.

What is specific heat capacity, and how does it characterize water?

Specific heat capacity is the amount of heat needed to raise the temperature of a substance by $1\,^\circ\text{C}$; water has a high specific heat capacity because it can absorb a lot of heat energy before its temperature increases.