answers

The atomic theory states that all matter is composed of atoms, which cannot be chemically broken down. Atoms are the fundamental building blocks of matter and retain their identity during chemical reactions.

Elements in chemistry are represented by symbols derived from their names. These symbols consist of one or two letters, such as H for hydrogen and Fe for iron.

Pure substances have a definite and uniform chemical composition. Elements are pure substances composed of one type of atom, while compounds are pure substances made up of two or more kinds of atoms in fixed ratios. Mixtures, on the other hand, are combinations of two or more pure substances that retain their individual properties.

Temperature is a measure of the average kinetic energy of particles. It indicates the level of thermal energy in a substance, with higher temperatures corresponding to greater average kinetic energy of the particles.

Atoms cannot be chemically broken down into simpler substances. They are the smallest units of matter that retain the properties of an element. However, atoms can undergo rearrangement and bonding during chemical reactions to form different substances.

The melting point of a substance is determined to assess its purity.

Mixtures can be classified as homogeneous (evenly distributed particles) or heterogeneous (non-uniform distribution).

Filtration, distillation, and chromatography are common separation techniques for mixtures.

Compounds have distinct properties different from their individual components, while mixtures retain the properties of their components.

Alloys are considered mixtures because they consist of different elements or compounds blended together, despite containing metallic bonding.