The Hearth and the Salamander Part 1 Practice Quiz

Evaporation is the process where liquid water molecules gain enough energy to enter the gas phase. This occurs at temperatures below boiling point when molecules escape from the surface.

An element is defined as a pure substance that consists entirely of one type of atom. It cannot be broken down into simpler substances by chemical means.

Combustion is a chemical reaction that requires oxygen to oxidize the fuel. Without oxygen, the reaction cannot proceed and fire will not be sustained.

Conduction is the process of heat transfer through direct contact and is most effective in solids due to their closely packed particles. It allows energy to pass from one particle to another efficiently.

Liquids maintain a fixed volume while taking the shape of their container. This contrasts with solids, which have both fixed volume and shape, and gases, which have neither.

A compound is formed when elements chemically bond in fixed ratios to form a new substance with distinct properties. In contrast, a mixture is a physical combination of substances that can vary in composition and be separated by physical means.

Radiation transfers energy through electromagnetic waves and does not require a physical medium. This allows energy to travel through the vacuum of space.

Metals possess free electrons that move through a 'sea' around positive ions, which allows for efficient electrical conductivity. This mobile electron system is a key characteristic of metal bonds.

An endothermic reaction is one that requires the absorption of heat energy from its surroundings. This absorbed energy is used to drive the chemical process, often resulting in a temperature drop.

The Law of Conservation of Energy is a core principle in physics asserting that energy remains constant in an isolated system. It can only change forms, not be created or destroyed, during physical or chemical processes.

During phase changes, the energy added is consumed in breaking or forming intermolecular bonds rather than increasing the kinetic energy of particles. As a result, the temperature of the substance does not change until the transition is complete.

The melting point of a substance is closely related to the strength of its intermolecular forces. Stronger forces require more energy to overcome, resulting in a higher melting point.

Activation energy is the threshold energy needed to start a chemical reaction. It represents the energy barrier that reactants must overcome to transform into products.

Exothermic reactions release energy in the form of heat, causing the surrounding temperature to rise. This release distinguishes them from endothermic reactions, which absorb heat.

Increasing the surface area of a reactant allows more particles to interact, thereby increasing the frequency of collisions. This typically leads to a higher reaction rate.

Reduction in a redox reaction specifically involves the gain of electrons by a chemical species. This lowers the oxidation state and is the counterpart to oxidation, where electrons are lost.

A balanced chemical equation reflects the conservation of mass, meaning the number of atoms for each element is the same on both sides of the reaction. This principle confirms that atoms are neither created nor destroyed in chemical processes.

Newton's Law of Cooling states that the rate at which an object loses heat is proportional to the temperature difference between the object and the environment. This allows predictions of cooling behavior based on that temperature gradient.

Minimizing heat loss or gain with the surroundings is crucial in calorimetry experiments. This isolation ensures that the energy measured is solely from the substance under investigation, providing accurate specific heat capacity values.

Catalysts speed up chemical reactions by lowering the activation energy required for the reaction to occur. Importantly, they are not consumed during the reaction, which allows them to be used repeatedly.