Question

part ii. in the spaces provided, describe the characteristics of the major categories of matter.

1. element -
2. compound -
3. mixture -

Explanation:

21. Element -

An element is a pure substance that cannot be broken down into simpler substances by chemical means. It is made up of only one type of atom. For example, hydrogen (H), oxygen (O), and gold (Au) are elements. Each element has a unique set of properties, including atomic number, atomic mass, and chemical reactivity, determined by the number of protons in its atomic nucleus.

22. Compound -

A compound is a pure substance composed of two or more different elements chemically combined in a fixed ratio. The elements in a compound are held together by chemical bonds, and the compound has properties distinct from those of its constituent elements. For instance, water (H₂O) is a compound made from hydrogen and oxygen in a 2:1 ratio, and table salt (NaCl) is a compound of sodium and chlorine. Compounds can be broken down into their constituent elements through chemical reactions.

23. Mixture -

A mixture is a combination of two or more substances (elements or compounds) that are physically mixed together but not chemically combined. The substances in a mixture retain their individual properties, and the ratio of the components can vary. Mixtures can be homogeneous (uniform composition, like salt dissolved in water) or heterogeneous (non - uniform composition, like a mixture of sand and water). The components of a mixture can be separated by physical methods such as filtration, distillation, or chromatography.

Answer:

1. Element - A pure substance with one type of atom, e.g., H, O, Au, can't be chemically broken down.
2. Compound - Pure substance with two+ elements in fixed ratio, e.g., H₂O, NaCl, has unique properties, broken down chemically.
3. Mixture - Combination of two+ substances, physically mixed, components retain properties, separated physically, e.g., salt - water (homogeneous), sand - water (heterogeneous).