Seperating Mixtures
What tool can separate sand from water?
A filter
What is a mixture?
Two or more substances physically combined
What does the Law of Conservation of Matter say?
Matter cannot be created or destroyed, only changed
What are the three main states of matter?
Solid, liquid, gas
Cutting paper is what kind of change?
Physical
How can you separate iron filings from sand?
Use a magnet
What is a solution?
A special type of mixture where one substance dissolves in another
A 50 g ice cube melts. How much does the water weigh?
50 g
Which state of matter keeps its shape?
Solid
Rust forming on metal is what kind of change?
Chemical
You have saltwater. How can you get the salt back?
Evaporate the water
In saltwater, which part is the solute and which is the solvent?
Salt = solute, Water = solvent
A 20 g candle burns; 5 g of wax remains. How much became gas?
20 − 5 = 15 g
When a liquid turns into a gas, what process is that?
Evaporation
Which type of change can be reversed easily?
Physical change
How could you separate a mixture of marbles and rice?
Use hand sorting or sieving
You dissolve 10 g of sugar in 90 g of water. What is the total mass of the solution?
10 + 90 = 100 g total
You mix 90 g of water and 10 g of sugar. What is the total mass?
100 g
When water vapor turns back into liquid, what process is that?
Condensation
Burning wood is what kind of change?
Chemical change
You start with 250 g of saltwater. After evaporation, 75 g of salt remains. How much water evaporated?
250 − 75 = 175 g
A student mixes 25 g of powder into 125 g of water but spills 10 g. What is the new total mass of the solution?
(25 + 125) – 10 = 140 g total
A jar has 300 g of liquid. After evaporation, 250 g remain. How much evaporated?
300 − 250 = 50 g
A block of ice (100 g) melts completely. What is the mass of the liquid water?
100 g (mass stays the same)
A scientist starts with 150 g of wood and ends with 30 g of ashes. Where did the missing matter go?
It turned into gases that went into the air