give the meaning of the following 1.elements
2.compounds
3.mixtures
4.pure substance
B.Give 5 example of
1.homogeneos mixture
2.heterogeneos mixture
3.pure substance
4.mixtures
5.elements
Answer:
1. Elements: Elements are substances that cannot be broken down into simpler substances by chemical means. They consist of atoms that all have the same number of protons in their nucleus. Examples of elements include hydrogen, oxygen, carbon, and gold.
2. Compounds: Compounds are substances composed of two or more different elements chemically combined in a fixed ratio. The constituent elements lose their individual properties and form new properties when combined. Examples of compounds include water (H2O), carbon dioxide (CO2), and sodium chloride (NaCl).
3. Mixtures: Mixtures are a combination of two or more substances that are physically intermingled, without any chemical bonding. The components in a mixture can be separated by physical means, such as filtration or evaporation. Examples of mixtures include air (a combination of gases), saltwater (a mixture of salt and water), and sand with pebbles.
4. Pure Substance: A pure substance refers to a single type of material that has a constant composition and properties. It can be either an element or a compound. Pure substances have well-defined melting and boiling points. Examples of pure substances include pure water (H2O), oxygen gas (O2), and gold (Au).
5. Examples:
a) Homogeneous mixture: Saltwater, sugar dissolved in water, air, vinegar, and brass (an alloy of copper and zinc).
b) Heterogeneous mixture: Trail mix, salad, soil, concrete, and oil and water mixture.
c) Pure substance: Iron (Fe), oxygen gas (O2), diamond (C), sulfur (S), and distilled water (H2O).
d) Mixtures: Soft drinks, milk, coffee with sugar, ink, and paint.
e) Elements: Hydrogen (H), oxygen (O), carbon (C), nitrogen (N), and gold (Au).