ELEMENTS, COMPOUNDS AND PHYSICAL AND CHEMICAL CHANGES
What is a physical Change?
A change that does not alter the chemical composition.
What is a solution?
A homogeneous mixture of two or more substances.
What is the formula for calculating speed?
Speed= Distance divided by Time
What is force?
A push or pull on an object.
What is thermal energy?
The total kinetic energy of particles in a substance.
What is the difference between an element and a compound?
Elements are pure substances, compounds are made of two or more elements chemically combined.
What is the solvent in a solution?
The substance that dissolves the solute.
If a car travels 150 kilometers in 3 hours, what is its speed?
50 Km/H
How does the first law apply to a book resting on a table?
The book will remain at rest until a force (like a push) acts on it
What is heat that is circulated through fluids like air or water called?
What is Convection?
Identify a common example of a physical change.
Melting ice.
What is the difference between a solute and a solvent?
Solute is dissolved; solvent does the dissolving.
Calculate the speed of a runner who completes a 400 meter race in 50 seconds.
Speed = 400 m ÷ 50 s = 8 m/s
What is inertia?
The tendency of an object to resist changes in its state of motion
Name three methods of heat transfer.
Conduction, convection, radiation.
What are indicators of a chemical change?
Color change, gas production, temperature change, precipitate formation
Name three things that increase the Rate of Dissolution.
Agitation
Surface Area
Temperature
If a cyclist is moving at a speed of 12 m/s, how far will they travel in 5 seconds?
Distance = Speed × Time = 12 m/s × 5 s = 60 m
Provide an example of a real-life situation that demonstrates the first law.
A passenger lunging forward in a sudden stop.
What is a Material that Reduces the Rate of thermal energy transfer.
What is Insulation.
Give two examples of Elements and two examples of compounds.
Examples:
Elements: Hydrogen, Oxygen, Gold, Silver.
Compounds: H2O, NaCl, CO2
What's the difference between concentration and dilution?
Concentration= Stronger Solution
Dilution= Weaker solution
Explain the difference between speed and velocity.
Speed is how fast an object moves; velocity includes direction.
Explain how the first law of motion relates to seatbelt use in cars
Seatbelts help counteract inertia during sudden stops
Explain the concept of thermal equilibrium.
When two objects at different temperatures come into contact, thermal energy flows until they reach the same temperature.