science post-test Flashcards
What is the definition of matter?
Anything that takes up space and has weight.
What is matter made of?
Matter is made of particles
How are the particles in the three common states of matter different?
Solid: The particles in a solid are close together and locked in position, they can vibrate a little but not move around. A solid has a fixed shape and volume.
Liquid: The particles in a Liquid are always sliding past one another. They still stay close together like a solid, but they are not a fixed shape. A liquid has a fixed volume but not a fixed shape.
Gas: The particles in a gas are far apart from each other and they can move however they want. The particles can bump into one another but they will always be far apart. A gas doesn’t have a fixed volume or shape, it can be compressed to be smaller or it can take up a bigger space than before.
What does it mean to have a fixed volume?
It means to take up a specific amount of space, no more, or no less.
What does it mean to have an unfixed volume?
It means that it could take up any amount of space, being able to take up more space or less space than it was first in.
What does it mean to have a fixed shape?
It means that it can’t change its shape, it will be one shape or form and it can’t change into a different shape.
What does it mean to have an unfixed shape?
It means that it can change its shape as much as it wants, if there is a wall with a hole at the bottom then a fixed shape couldn’t go through unless it is the shape of the hole, but an unfixed shape could simply change shape and slide through.
What is a solution?
A solution is when you add one or more substances to something, usually a liquid, and it dissolves into the liquid, then it is a solution.
What is a substance? Give an example.
A substance is a material where each part of it is made of the same type of particle. Each particle has its own characteristics, called properties. Sugar is a substance.
What is a mixture? Give an example.
A mixture is a combination of two or more substances where their particles aren’t joined together. An example of a mixture is sugar water.
What are properties that you can use to identify a substance? For example: color, hardness, etc… (Make sure you understand what each of these means. For example, in order to check hardness, try scratching the material.)
Properties you can see: Color, size, shape, shininess, hardness.
Properties that are harder to see: Solubility, Electric conductivity, thermal conductivity, the ability to change.
What properties are signs of a substance changing into a new substance?
Melting, Freezing, Evaporating, condensation.
What is a state change?
A state change is when a substance changes its state of matter, like from solid, to liquid.
How do you know when a substance has changed into a new substance (if a reaction has occurred)? What signs should you look for? For example, gas formation is one sign of a reaction.
If it bubbles or fizzes. if it melts, or freezes, if it evaporates, if it changes color.
What can cause properties of matter to change? Hint: There are three main ways.
Heating the substance, Cooling the substance, and Mixing substances.
