Chemistry: Matter & Chemical Properties

Matter and Its Properties

• Matter is anything that possesses mass and occupies space, categorized into pure substances and mixtures.
• Mass refers to the amount of matter contained in an object.
• States of matter include solid, liquid, and gas, which define the phase of a substance.

Chemical and Physical Properties

• Magnetism describes a material's ability to attract or be attracted by a magnet.
• Density is the mass per unit volume, indicating how tightly matter is packed together.
• Solubility is the capacity of a substance to dissolve in another substance, a common physical property.
• Thermal energy refers to energy that leads to changes in temperature between materials, impacting states of matter.
• Electrical energy involves the energy associated with electric charges, essential in many technological applications.
• Insulators hinder the flow of electric current or heat, while conductors facilitate it.

Characteristics of Properties

• Extensive properties, such as mass and volume, depend on the quantity of matter in a sample.
• Intensive properties, like density and melting point, remain unchanged regardless of the amount of substance present.
• Compressibility measures how much the volume of matter can decrease under applied pressure.

Changes in Matter

• Physical properties can be observed without altering the substance's identity (e.g., color, luster).
• Chemical properties involve a substance's ability to undergo chemical changes, forming new substances.
• Physical changes do not result in a new substance, while chemical changes produce one or more new substances.

States and Changes of Matter

• Solids have a definite shape and volume; liquids have a definite volume but take the shape of their container; gases have neither definite shape nor volume.
• Melting point is the temperature at which solids turn into liquids; freezing point is the temperature at which liquids solidify.
• Evaporation is the transition from liquid to gas, whereas condensation refers to gas changing to liquid.

Mixtures and Solutions

• Homogeneous mixtures have a uniform composition throughout, while heterogeneous mixtures show uneven distribution of components.
• A solution is a specific type of homogeneous mixture containing two or more substances.
• Pure substances are comprised of only one type of matter, possessing fixed properties that distinguish them from mixtures.

Additional Properties of Materials

• Ductility refers to a material's ability to be drawn into wires.
• Malleability is the ability to be hammered or rolled into thin sheets without breaking.
• Luster indicates how a substance reflects light, an important property in materials like metals.
• Precipitate describes a new solid that forms in a solution during a chemical reaction, sinking to the bottom of the container.