Chemistry Flash Cards

A physical property is a characteristic of a substance that can be observed or measured without changing the composition of the substance. It includes properties like color, density, melting point, and odor.

A mixture refers to a physical combination of two or more substances without any chemical bonding between them, unlike a pure substance with uniform composition which contains only one type of substance.

An exothermic process involves the release of energy, typically in the form of heat.

The mass number represents the total number of nucleons (protons and neutrons) in an atom's nucleus, providing information about its atomic mass.

Isotopes are atoms of the same element with varying numbers of neutrons, which results in different mass numbers. This variation in neutrons does not affect the atomic number or the number of protons in the atom.

Valence electrons play a crucial role in determining the chemical properties of an element, and they are involved in the formation of chemical bonds.

Electronegativity specifically refers to the ability of an element's atoms to attract electrons in chemical bonds, not to its ability to conduct electricity, number of electrons in the outer energy level, or weight in atomic mass units.

A cation is a positively charged ion formed by removing electrons from the neutral atom, leading to a more stable electron configuration.

Covalent bonds are formed when two atoms share electrons to achieve a stable electron configuration. This sharing of electrons results in the formation of a molecular bond.

Chemical properties deal with the behavior of substances in reactions, not physical characteristics like state, taste, or color.

Combustion reactions involve the reaction of a substance with oxygen, not with hydrogen, nitrogen, or carbon dioxide. The products of a combustion reaction are typically carbon dioxide and water.

An endothermic reaction absorbs heat energy, unlike an exothermic reaction which releases heat energy. It is important to distinguish between the two types of reactions based on the direction of heat flow.

A synthesis reaction is a type of chemical reaction where two or more simple substances combine to form a more complex product. It is the opposite of a decomposition reaction where a single compound breaks down into multiple simpler substances. The correct answer highlights the key characteristic of a synthesis reaction, which is the combination of substances to form a single product.

A phase transition specifically refers to a change in physical state, not color, chemical composition, or weight.

A decomposition reaction is a type of chemical reaction where a single compound breaks down into two or more simpler substances, contrary to the other options provided.

Organic compounds are defined by their basis on the element carbon and can contain a variety of other elements. The presence of carbon-hydrogen bonds is a common characteristic of organic compounds.

Activation energy is a key concept in understanding chemical reactions and is essential for determining reaction rates and mechanisms.

A catalyst is a substance that speeds up a reaction without being consumed or changed itself. It works by lowering the activation energy barrier for the reaction to occur.

Surface tension is a property of liquids that describes the force that causes the surface of the liquid to behave like a stretched elastic membrane. It is not related to evaporation, electrical conductivity, or buoyancy.

Sublimation is a phase transition process in which a substance changes from a solid to a gas without passing through the liquid state. It involves the direct conversion of a solid substance into a gaseous form under specific pressure and temperature conditions.

Products in a chemical reaction are the end result substances formed after the reaction is completed.

Condensation is the phase change from gas to liquid, not from liquid to gas. It is also different from the phase change from solid to gas. Cloud formation is related to condensation but not the definition of condensation itself.

A strong acid fully disassociates in water, releasing all of its hydrogen ions. This characteristic distinguishes it from weak acids, which only partially disassociate.

An unsaturated solution is one in which there is room for more solute to be dissolved. This contrasts with saturated solutions, which have the maximum amount of solute that can be dissolved, and supersaturated solutions, which contain more solute than normally possible. Diluted solutions refer to having a lower concentration of solute compared to solvent.

Neutrons are neutral particles with no charge, unlike protons that are positively charged. They are not identical to electrons, which are negatively charged and do not exist in the nucleus of an atom. Neutrons are stable particles and not inherently harmful as implied by the incorrect answers.

A buffer solution is specifically designed to resist changes in pH when small amounts of acids or bases are added, making it crucial in various industries and scientific experiments.