States of Matter
This state has a definite shape and a definite volume.
What is a solid?
When heat is added, particles do this.
What is move faster?
Solid → Liquid
What is melting?
The smallest particle of matter.
What is an atom?
CO₂ contains carbon and this element.
What is oxygen?
Particles in this state are close together but can slide past each other.
What is a liquid?
This energy is the total kinetic energy of particles in a substance.
What is thermal energy?
Liquid → Gas
What is evaporation/boiling?
A substance made of only one type of atom.
What is an element?
How many oxygen atoms are in CO₂?
2
This state has no definite shape or definite volume.
What is a gas?
This measures how hot or cold something is.
What is temperature?
Gas → Liquid
What is condensation?
A substance made when two or more elements join chemically.
What is a compound?
This shows what elements and how many atoms are in a compound.
What is a chemical formula?
Explain why solids keep their shape.
Their particles are tightly packed and only vibrate in place.
Explain how heat affects the movement of particles.
Heat increases particle movement; particles speed up and spread apart.
Describe what happens during freezing.
Heat is removed, particles slow down, and the liquid becomes a solid.
What is the difference between elements and compounds?
Elements contain only one type of atom; compounds contain two or more elements bonded together.
What elements are in C₆H₁₂O₆?
Carbon, hydrogen, and oxygen.
Describe how the arrangement AND movement of particles change as a substance goes from a solid → liquid → gas.
Particles in a solid are tightly packed and only vibrate. In a liquid, they are still close but can slide past each other. In a gas, particles are far apart and move very fast in all directions.
Explain why heating a substance increases its thermal energy but doesn’t always change its temperature right away.
Some added heat is used to change the substance’s state, not to increase particle speed, so temperature stays the same during melting or boiling even though thermal energy is still increasing.
Why does evaporation happen faster on a hot, dry, or windy day compared to a cool or humid day?
Because higher heat gives particles more energy to escape into the air, and dry or windy air removes water vapor quickly, allowing more liquid particles to evaporate.
Explain why water (H₂O) is considered a compound and not an element, and describe what must happen at the particle level to break it into hydrogen and oxygen.
Water is a compound because it contains two different elements chemically bonded. To break it into hydrogen and oxygen, chemical bonds between atoms must be broken, which requires a chemical reaction.
A molecule has the chemical formula C₂H₆O.
Explain how you know this is a compound, and list the total number of atoms in one molecule.
It is a compound because it contains more than one element (carbon, hydrogen, and oxygen). Total atoms: 2 carbon + 6 hydrogen + 1 oxygen = 9 atoms.