Learn About Separating Mixtures

Explanation
The correct answer is physically removing particles. Sorting involves the process of physically separating different particles based on their properties or characteristics. This can be done by hand or by using various mechanical techniques such as sieving, filtering, or using machines like centrifuges. Dissolving the mixture, heating, or using a sieve are not specifically related to the process of physically removing particles, hence they are not the correct answers.

Explanation
A complex mixture is composed of a combination of mechanical mixtures and solutions. This means that it contains both substances that are physically mixed together but remain separate, as well as substances that are dissolved in a solvent. The mechanical mixture refers to the presence of insoluble components that can be easily separated, while the solutions refer to the presence of soluble components that are evenly distributed throughout the mixture. Therefore, a complex mixture is a heterogeneous combination of both mechanical mixtures and solutions.

Explanation
Recycling plants use magnets to remove metal because magnets are attracted to materials that contain iron or other magnetic metals. By using magnets, recycling plants can easily separate metal items from other materials, such as plastics, paper, and styrofoam, making the recycling process more efficient. This allows the metal to be recycled separately and prevents it from contaminating other materials.

Explanation
To separate pepper from salt, one can dissolve the mixture in water. Salt is soluble in water, while pepper is not. By dissolving the mixture, the salt will dissolve, leaving the pepper behind. Then, the solution can be filtered to separate the dissolved salt from the pepper. This method exploits the difference in solubility between the two substances, allowing for an effective separation.

Explanation
A sieve would be the best choice to remove large branches when treating water at the sewage treatment plant. A sieve is a device with small holes or mesh that allows smaller particles to pass through while trapping larger objects. In this case, the sieve would effectively separate and remove the large branches from the water, ensuring that they do not interfere with the treatment process or cause any blockages further downstream.

Explanation
The best way to remove oil and sludge from water at the treatment plant would be through the process of floating. This method involves allowing the oil and sludge to rise to the surface of the water, where it can be skimmed off or collected using specialized equipment. Floating is effective because oil and sludge have a lower density than water, causing them to naturally separate and float on top. This allows for easy removal and helps to ensure that the treated water is clean and free from contaminants.

Explanation
A centrifuge machine can separate blood into its parts quickly because it uses centrifugal force to spin the blood at high speeds. This force causes the heavier components, such as red blood cells, to settle at the bottom while the lighter components, such as plasma, rise to the top. This separation process is efficient and allows for the quick isolation of different blood components for further analysis or use in medical procedures.