density
What is the formula for calculating density?
Density = Mass / Volume
What is a physical change?
A change that affects one or more physical properties of a substance without altering its chemical composition.
What are physical properties?
Characteristics that can be observed or measured without changing the substance's composition.
What is energy?
The ability to do work or cause change.
What does the law of conservation of energy state?
Energy cannot be created or destroyed, only transformed.
If an object has a mass of 20 grams and a volume of 5 cm³, what is its density?
4 g/cm³
Give an example of a chemical change.
Rusting of iron or burning wood.
What is an example of a chemical property?
Flammability or reactivity with acid.
What are two types of energy?
Potential energy and kinetic energy.
How does this law apply to a closed system?
Answer: In a closed system, the total energy remains constant, despite transformations
Why do substances with a density less than water float?
Answ
Because they are less dense than water, so they displace less water than their weight.
What is the main difference between a physical change and a chemical change?
A physical change does not change the substance's chemical identity, while a chemical change does.
How can you determine whether a property is physical or chemical?
If the property can be observed without changing the substance, it is physical; if it requires a change in the substance, it is chemical.
How is thermal energy related to temperature?
Answ
Thermal energy is the total kinetic energy of the particles in a substance, which is measured as temperature
Why is understanding energy conservation important in science?
It helps predict how energy will behave in different processes and systems
How does temperature affect the density of most substances?
Most substances decrease in density as temperature increases.
What are some indicators that a chemical change has occurred?
Color change, gas production, temperature change, formation of a precipitate.
List three physical properties of water.
Colorless, odorless, and has a boiling point of 100°C.
What is the law of conservation of energy?
Answer: Energy cannot be created or destroyed, only transformed from one form to another.
Give an example of the law of conservation of energy in a practical scenario.
In a pendulum, the energy shifts between potential and kinetic, but the total energy remains constant.
What is the relationship between density and buoyancy?
An object will float if it is less dense than the fluid it is in, and sink if it is more dense.
Describe how a rotting fruit represents a chemical change.
The fruit undergoes a chemical reaction that alters its composition, resulting in new substances.
What is the significance of a substance's boiling point as a physical property?
It indicates the temperature at which a substance changes from a liquid to a gas.
Provide an example of energy transformation in a roller coaster.
Potential energy at the top is converted to kinetic energy as it descends.
How does the law of conservation of energy relate to chemical reactions?
The total energy before and after a chemical reaction remains the same, even though it may change forms