Solids, Liquids, Gases
In which state of matter do the particles move the fastest?
Gas. These have the most energy allowing them to spread in different directions.
What is it called when a solid turns into a liquid?
melting.
How would you define a mixture?
A mixture is a combination of two or more substances in which each substance retains its own properties and can be physically separated.
What is a pure substance AND provide an example of one.
It is made up of only one type of particle and cannot be separated into other substances by physical means.
oxygen
Why do car tires feel harder (more inflated) on a hot day and softer (less inflated) on a cold day?
Heat causes the air in the temperatures to expand, whereas cold temperatures causes it to contract.
Why do solids have a fixed shape but liquids do not?
Solids have a fixed shape because their particles are tightly packed and only vibrate in place, which keeps the structure rigid. The forces between the particles in a solid are strong enough to hold them in place, preventing the substance from changing shape.
When you freeze water into ice, does it still have the same mass?
Yes, when you freeze water into ice, it still has the same mass.
This is a physical change, not a chemical one.
Name the two components that make up a homogenous mixture AND clarify each two in an example.
Solvent and the solute.
Is gold a pure substance or a mixture?
it is a pure substance and element on the periodic table.
Why does ice float in water, and how does this property benefit life in the environment?
Water becomes less dense when it freezes.
This property benefits life in the environment because it insulates the water beneath it, helping to maintain a more stable temperature for aquatic life in cold climates.
What happened to the speed of particles when they get heated up?
As the temperature rises, the particles gain more energy, which causes them to move faster.
What process happens when water in a puddle disappears over time?
evaporation. Liquid turns into water vapor.
Is soil a heterogenous or homogenous mixture?
Soil is considered a heterogeneous mixture because it contains a variety of different components, such as sand, clay, organic matter, minerals, and sometimes water or air.
Is air classified as a pure substance? AND Explain your reasoning.
Air is a mixture because it is made up of different gases, primarily nitrogen, oxygen, carbon dioxide, argon, and small amounts of other gases, along with water vapor
When David left a can of soda in his parents car on a hot summer day, what was the result?
Why did this happen?
It exploded because the heat caused the carbon dioxide (gas) to expand. This increased the pressure and caused the can to burst.
Why do liquids take the shape of their container but solids do not?
Liquids take the shape of their container because their particles are close together but can move past each other. This allows the liquid to flow and adjust to the shape of whatever container it is in. They are not as tight and rigid as solids.
What change of state occurs when a gas turns into a liquid AND provide an example of this.
condensation.
water vapor turning to liquid on a cold glass.
If you mix oil and water and shake it up, why does the mixture separate into two layers after some time? What kind of mixture is this?
because oil and water do not mix on a molecular level. This happens because water molecules are polar (they have a slight charge), while oil molecules are nonpolar. Denser water goes to the bottom, whereas the lighter oil floats on top.
What is a compound AND provide an example?
A compound is a substance made up of two or more different elements that are chemically bonded together.
Water H2O
Salt NaCl
Why does a hot air balloon rise when the air inside is heated?
A hot air balloon rises when the air inside is heated because heating the air causes the air molecules to move faster and spread out. As the air molecules spread out, the air inside the balloon becomes less dense than the cooler air outside.
A gas is compressed into a smaller space. How do the particles behave differently than before?
When a gas is compressed into a smaller space, the particles are forced closer together. This increases the collisions they make with each other which creates pressure. Think of the air when you pump it inside of your bike
what is it called when a gas changes to a solid?
deposition
An example of deposition is the formation of frost on a cold surface, where water vapor in the air directly becomes solid ice.
If we mixed sugar and water together to create a homogenous mixture, would we be able to again separate the two? Why or why not?
You would need to evaporate the water over time using heat. This would change the liquid to a gas.
Can a mixture of sugar and water be considered a pure substance? Why or why not?
While sugar and water are both pure substances on their own, when they are mixed together, they form a mixture. In a mixture, the components retain their individual properties and can be physically separated.
Why do people sometimes feel cold after getting out of a swimming pool, even on a hot day? Explain using evaporation and particle energy.
Because of evaporation. When you leave the pool, the water on your skin starts to evaporate. As the water evaporates, this turns to a gas and it steals the heat from your body to do so!