Classification Of Matter Quiz

Iron is classified as an element because it is a pure substance that cannot be broken down into simpler substances by chemical means. It consists of only one type of atom, specifically iron atoms. Elements are the building blocks of all matter and are listed in the periodic table. Iron is commonly found in the Earth's crust and is known for its strength and ability to form alloys with other elements.

Gold is a chemical element with the symbol Au and atomic number 79. It is a dense, soft, malleable, and ductile metal. Gold is a pure substance that cannot be broken down into simpler substances by chemical means.

Mercury is an element because it cannot be broken down into simpler substances through chemical reactions. It is a unique and pure substance made up of only one type of atom, specifically mercury atoms. Elements are the building blocks of all matter, and there are 118 known elements on the periodic table.

A vegetable soup is considered a heterogeneous mixture because it is made up of multiple different components that are not evenly distributed throughout the mixture. In vegetable soup, there are various vegetables, spices, and broth that are all combined together. These components can be seen and distinguished from one another, and they do not blend together to form a uniform composition.

Carbon dioxide is a compound because it is composed of two different elements, carbon and oxygen, chemically bonded together. A compound is a substance made up of two or more elements that are chemically combined in a fixed ratio. In the case of carbon dioxide, one carbon atom is bonded to two oxygen atoms, forming a stable compound with specific properties.

Boiling water at 100 degrees Celsius is a physical change because it involves a change in the state of matter from liquid to gas, without altering the chemical composition of the water molecules. The temperature increase causes the water molecules to gain enough energy to overcome the intermolecular forces and transform from a liquid  a gaseous state. This change is reversible, as the water can be cooled down to return to its liquid state without any chemical reactions occurring.

Table salt, also known as sodium chloride, is a compound. A compound is a substance composed of two or more elements chemically bonded together. Table salt is made up of sodium (Na) and chloride (Cl) ions that are held together by ionic bonds. This means that sodium chloride has a fixed ratio of sodium to chloride atoms, giving it a distinct chemical composition.

Coffee is a homogeneous mixture because it is made up of different substances that are uniformly distributed throughout. When coffee is brewed, the water, coffee beans, and any other additives such as sugar or milk, combine to form a single phase. This means that no matter where you sample the coffee from, it will have the same composition and properties. There are no visible differences or separate phases within the mixture, making it homogeneous.

A pure substance has a fixed and uniform composition. Gold, water, and diamond are all pure substances with specific chemical compositions. Saltwater is a mixture of salt and water, meaning its composition can vary, making it not a pure substance.

Tap water is a homogeneous mixture because it is composed of multiple substances (such as minerals, dissolved gases, and impurities) that are uniformly distributed throughout the water. This means that the composition of tap water is similar throughout, regardless of where it is sampled from.