What is the primary reason for separating substances from a mixture?

The primary reason is to extract useful substances from a mixture, allowing for different components to be utilized in various ways.

A mixture is defined as a substance composed of two or more substances, where each component retains its unique property. True or False?

True.

Fill in the blank: Distilled water is considered a ___ substance because each particle has the same unique property.

Pure

What is the difference between a pure substance and a mixture?

A pure substance has uniform properties throughout, while a mixture consists of two or more substances that retain their individual properties.

Riddle: I am everywhere, yet you can’t see me. I’m made of many gases mixed together. What am I?

Air.

True or False: A substance is called pure when it contains more than one type of particle.

False. A substance is called pure when each particle has the same unique property.

What method is primarily used for separating unwanted materials when they are in small quantities and visibly different in shape or color from useful materials?

Handpicking is used for separating unwanted materials that are in small quantities and differ in shape, size, or color from useful materials.

Fill in the blank: Threshing is used to separate ___ from the harvested stalks.

Seeds

What is the primary function of sieving in the separation of solids?

Sieving is used to separate particles based on size, where larger particles are retained and smaller ones pass through the sieve.

Riddle: I have holes and help you separate the small from the large. What am I?

A sieve.

Fill in the blank: When threshing is done using animals, they are tied to a ___ to walk over the harvested stalks.

Pole

What is the process of separating lighter particles from heavier ones using wind called?

Winnowing

In the winnowing process, the husk is carried away by the wind while the ___ grains fall to form a separate heap.

Heavier wheat

True or False: A combine harvester is used to harvest, thresh, and winnow crops in one operation.

True

What two operations does a combine harvester perform?

It harvests and threshes.

What is the process called when insoluble particles settle down at the bottom of a liquid?

Sedimentation

True or False: Decantation involves mixing a solid with a liquid to create a homogeneous solution.

False. Decantation involves pouring off the liquid from the settled solid, not mixing.