States of Matter
What is the process called when a liquid turns into a gas?
Evaporation
Give two examples of a physical change.
Anything melting, boiling, freezing, breaking, etc
Give two examples of a chemical change
Burning wood and rusting iron
What are the three main subatomic particles in an atom?
Protons, neutrons, and electrons.
What are the three states of matter?
Solid liquid and gas
What happens to the particles of a substance when it changes from a solid to a liquid?
The amount of energy in the particles increases, the particles move more and move further apart. The particles are able to slide past each other
Does a physical change create a new substance? Why or why not?
No, because the substance keeps its original chemical composition, even though its form or state may change.
How can you tell that a chemical change has occurred?
Signs include color change, gas production (bubbles), temperature change, formation of a precipitate, or light emission.
Where are protons, neutrons, and electrons located in an atom?
Protons and neutrons are in the nucleus, while electrons move around the nucleus in electron shells.
What is an atom?
An atom is the smallest unit of an element that retains its chemical properties
How does the arrangement of particles in a gas differ from those in a solid?
Particles in a gas have much more energy - they are spaced far apart and move quickly. Particles in a solid are arranged in a pattern and are very close together. They vibrate in place.
Why is dissolving sugar in water considered a physical change?
Because it can be reversed and because the sugar and water are not changed into a new substance
What is the difference between a physical change and a chemical change?
A physical change does not create new substances and is often reversible, while a chemical change creates new substances with different properties and is usually irreversible.
What is the charge of each subatomic particle?
What is the difference between an element and a compound?
An element is made of only one type of atom, while a compound is made of two or more different atoms chemically bonded together
Explain why a solid keeps its shape, but a liquid takes the shape of its container.
Because the particles are more spaced out and are able to flow. Solids have a defined structure
Why does cutting a piece of paper into smaller pieces count as a physical change?
Because no new substance is formed. The paper only changes size
Why is cooking an egg considered a chemical change?
The heat causes the proteins in the egg to permanently change structure, forming a new substance that cannot return to its raw state.
The Atomic Mass of an element is the combined number of what two subatomic particles?
Protons and Neutrons
Why do some elements react more easily than others?
Because of their electron arrangement—elements with nearly full or empty outer shells tend to react more easily to achieve a stable configuration
How do temperature and pressure affect the state of matter of a substance?
Increase the energy in the particles and the space between them which increases the pressure. Can cause change in state
How do changes in temperature and pressure affect physical changes in matter? Provide an example.
Temperature and pressure can cause substances to change state. For example, increasing temperature can turn ice into water (melting), while reducing pressure can cause water to boil at a lower temperature.
What is a precipitate, and how does its formation indicate a chemical change?
A precipitate is a solid that forms when two liquids react chemically. Its appearance indicates that a new substance has been created.
Why do atoms usually have no overall charge?
Because they have an equal number of protons (positive charge) and electrons (negative charge), which cancel out.
What is the Law of Conservation of Mass?
This law states that matter cannot be created or destroyed in a chemical reaction; the total mass of reactants always equals the total mass of products.