Phases of matter
Matter is anything that has mass and takes up ______.
Space (volume)
A pure substance made of only one type of atom.
Element
Which one is a physical property?
A) Flammability
B) Density
C) Reacts with oxygen
D) Corrosiveness
B. Density
A solid has settled at the bottom of a container, and you want to carefully pour off the liquid without disturbing the solid. What technique should you use?
Decantation
A small cup of coffee and a large thermos are both at 80°C. Which one has more thermal energy, and why?
The large thermos, because it has more molecules
In this state, particles are very close together and mainly vibrate.
Solid
A pure substance containing two or more elements that are chemically combined.
Compound
TRUE OR FALSE: A chemical change produces a chemically different substance
True
A mixture contains salt, sand, and water. You filter the mixture first. What remains on the filter paper?
Sand
A hot object and a cold object are placed together. What will happen to the heat until they reach the same temperature?
Heat will move from the hot object to the cold object.
This state has a definite volume but takes the shape of its container
Liquid
A mixture that is uniform in composition.
Homogeneous mixture
A piece of metal is cut into two smaller pieces. Is this a physical change or chemical change?
Physical change
You need to separate the salt from the saltwater after filtration. Which method would allow you to recover the salt?
Evaporation
Which statement correctly compares temperature and thermal energy?
A) Both depend on the amount of substance.
B) Temperature depends on mass, but thermal energy does not.
C) Temperature is based on average particle motion, while thermal energy depends on the total energy of the particles.
D) They are the same thing.
C(Temperature = average particle motion; thermal energy = total particle energy
In this state, particles are far apart and move very quickly
Gas
In a solution, the substance being dissolved and present in the lesser amount.
Solute( baba you should know this) Mohammad
Which situation is evidence of a chemical change?
A) Ice melting
B) Water boiling
C) A new solid precipitate forming
D) Cutting paper
C) A new solid precipitate forming
A machine spins a mixture very fast to separate parts that have different ______.
Densities
The reactants in a reaction have MORE chemical potential energy than the products. What happens to the extra energy?
A) It is absorbed by the system.
B) It is released to the surroundings.
C) It disappears.
D) The reaction stops.
B) It is released to the surroundings.
This high-temperature state occurs when atoms lose their electrons.
Plasma
The substance doing the dissolving and present in the larger amount.
Solvent
Match the property to the correct category:
Density — Physical or Chemical?
Flammability — Physical or Chemical?
Reacts with water — Physical or Chemical?
Density = Physical; Flammability = Chemical; Reacts with water = Chemical
A mixture contains water and alcohol. Alcohol boils at 78°C and water boils at 100°C. When heated, which substance vaporizes first, and why?
Alcohol, because it has the lower boiling point
Baba special question:)
What is the scientific definition of pH?
A) The measure of hydrogen ion concentration in a solution
B) The measure of temperature in a solution
C) The measure of how much water is in a solution
D) The measure of the mass of a solution
A) The measure of hydrogen ion concentration in a solution