Elements, Compounds, and Mixtures
What is an element? Give one example
Elements are substances made from one kind of atom. Any element
What separating technique is used to separate sand and water?
the sand stays on the filter paper, and water passes through
What does the kinetic molecular theory explain?
The kinetic molecular theory explains the physical properties of matter (solids, liquids, and gases) by describing particles in terms of Energy, Arrangement and motion
What are the six main changes of state?
Melting, Freezing, Boiling, Condensing, Sublimation,
and deposition
what are the 3 main states of matter
Solid liquid and gas
What is the main difference between a compound and a mixture?
A compound is chemically combined; a mixture is physically combined.
Explain solvent extraction and give one example
What happens to the motion of particles when the temperature increases?
They move faster and have more kinetic enegy
What happens to particles when a solid melts?
They gain energy. vibrate faster and move apart
How to convert Kelvin to Celsius
Kelvin-273.15=-Celsius
Why can the components of a mixture be separated but not those of a compound?
Because in mixtures, substances keep their properties . In compounds, atoms are chemically bonded
Explain recrystallization and give one example
purifies impure crystals by dissolving them in a hot solvent and then allowing the solution to cool slowly. Pure crystals form, while impurities remain dissolved in the solvent.
How does kinetic molecular theory explain the diffusion of perfume in air?
gas particles spread out until evenly mixed
Why does boiling require more energy than melting?
Because all bonds between particles must be broken not weakened
what will happen to particles at absolute zere
particles have no kinetic energy
Explain why water is considered a compound and not a mixture?
It has hydrogen and oxygen atoms chemically bonded in a fixed ratio
explain Filtration
Filtration is a technique used to separate an insoluble solid from a liquid. The mixture is poured through filter paper, which allows the liquid (filtrate) to pass through while trapping the solid particles
Describe how kinetic molecular theory explains the expansion of gases when heated.
Heating increases particle spread and collisions. Push them farther apart.
Describe what happens to particle arrangement, movement, and energy during condensation.
Particles lose energy and move closer and become ordered
explain evaporation
separates a soluble solid from its solvent by heating. The liquid solvent changes into vapor and escapes, leaving the solid behind.
explain crystallization
Crystallization is used to obtain pure crystals of a soluble solid from a solution. The solution is heated until saturated, then cooled slowly so the solute forms crystals as it becomes less soluble in cooler conditions.
simple distillation
Simple distillation separates a solvent from a solution. The mixture is heated until the solvent boils and vaporizes, then the vapor is condensed back into liquid and collected separately.
explain fractional distillation
Fractional distillation separates two or more miscible liquids with different boiling points. A fractionating column ensures repeated vaporization and condensation, so liquids with lower boiling points distill first.
Explain chromatography
: Chromatography separates mixtures of soluble substances based on their different solubilities and attractions to the stationary (paper) and mobile (solvent) phases. Substances that are more soluble in the solvent travel farther.
Explain centrifugation.
: Centrifugation separates mixtures by density by spinning them rapidly. Denser components move to the bottom of the tube, while lighter components remain at the top.