Powders & Crystals
Unit 2 Powders and Crystals
Our second unit is a chemistry unit where we will learn about properties, powders, crystals, acids, bases, mixtures, solutions, and chemical reactions.
A powder is a substance that has been ground or pulverized into finely dispersed, loose, and solid particles.
A crystal is the solid form of a substance in which the atoms are arranged in repeating patterns.
Additional Vocabulary to Know
A substance with a pH less than 7 (the lower the number, the stronger the acid). Has a sour taste and is capable of reacting with a base.
Having the properties of an acid
A substance with a pH higher than 7 (the higher the number, the stronger the base). Is bitter to taste, slippery to the touch, and capable of reacting with an acid.
Having the properties of a base.
The process of determining the chemical makeup of a substance by observing its response to a series of tests.
Two substances react to each other in a way that produces a change in each of them.
Made of 2 or more parts, elements, or ingredients.
A solid form of a substance in which the atoms are arranged in repeating patterns.
When something is mixed into a liquid in an evenly distributed way, and is usually no longer visible as a separate substance.
Has neither a definite volume or a definite shape. It takes on the volume and shape of its container.
A substance that shows – by change of color – that another particular substance is either present or absent.
Can’t be dissolved.
Has a definite volume, but no definite shape. Takes on the shape of the container that holds it.
A substance changes from a solid to a liquid state.
A combination of 2 or more substances that are not changed chemically by being combined and can be easily separated.
A substance that is neither acidic or basic; has a pH of 7.
A tiny piece of something.
The scale on which scientists measure how acidic or basic a substance is.
A substance that has been ground or pulverized into finely dispersed, loose, solid particles.
An educated guess of something that will happen.
An observable characteristic or trait, such as color, shape, size, texture, smell, sound, etc.
How we receive information from the world through sight, touch, taste, smell, and sound.
Has a definite shape and volume. Its shape and size can be measured.
Mixture in which one substance is dissolved in another.
It is important to remember that mixtures start in pieces. Then you combine these pieces together. You can pull the pieces of a mixture apart again and will end up with the same molecules (in the same amount) you started with.
Solutions are groups of molecules that are mixed up in a completely even distribution. For example, when you combine sugar and water, sugar dissolves and is spread throughout the glass of water. The sugar is the solute (substance to be dissolved) and the water is the solvent (the one doing the dissolving).
The pH scale runs from pH 0 to pH 14. Neutral solutions are exactly 7. Acidic solutions have pH values less than 7. Alkaline solutions have pH values of more than 7.
A chemical reaction is a change that produces one or more new substances from some starting materials. Examples are iron rust, burning candle, fireworks, etc.