Mixtures
What is a combination of two or more substances that can be easily separated?
Mixture
What happens to particles when a solid melts?
The particles gain energy and move apart.
What is the formula for calculating density?
Density = Mass/Volume
What is the term for the maximum amount of solute that can dissolve in a solvent?
Solubility
What is a sign that a chemical change has occurred?
Change in color, temperature, or production of gas.
What type of mixture has a uniform composition throughout?
Homogeneous mixture
What phase change occurs when a liquid turns into a gas?
Vaporization
How does density change when a substance is heated?
Density decreases as a substance is heated.
What happens to the solubility of most solids as temperature increases?
Solubility increases.
What happens to the atoms in a substance during a chemical change?
They rearrange to form new substances.
Name a method used to separate components of a mixture based on their size.
Filtration
Describe what happens to the motion of atoms when heat is added to a substance.
The particles move faster and spread apart.
If you have two objects of equal volume but different masses, which one has a higher density?
The one with greater mass has higher density.
What is an example of a soluble substance in water?
Salt or sugar
Give an example of a chemical change that happens when wood burns.
Combustion of wood.
In a salad, what type of mixture is represented?
Heterogeneous mixture
What is the process called when a gas turns into a liquid?
Condensation
Why do some objects float while others sink in water?
Objects with density less than 1 g/cm³ float, while those with higher densities sink.
How does the particle size of a solute affect its solubility?
Smaller particles dissolve faster.
What is the difference between a physical change and a chemical change?
Physical changes do not change the substance's identity; chemical changes do.
What is the difference between a homogeneous mixture and a heterogeneous mixture?
Homogeneous mixtures have a uniform composition; heterogeneous mixtures do not.
What happens to water molecules when ice is heated?
The water molecules gain energy and move faster.
How can you determine whether a substance is a liquid, solid, or gas based on density?
A higher density indicates a solid, lower indicates a liquid or gas.
What do we call a solution that contains more solute than it can normally hold at a given temperature?
Supersaturated solution
What do we call a chemical reaction that absorbs heat from its surroundings?
Endothermic reaction