States of Matter
What are the four main states of matter?
Gas, Liquid, Solid, Plasma
What is the formula for density?
Density = Mass ÷ Volume
What tool measures mass
A balance (triple beam or digital)
What change turns a solid into a liquid?
Melting
Why do ice cubes float in water?
They are less dense than liquid water
Which state of matter has a definite shape and volume?
Solid
If an object has a density greater than water, will it sink or float?
Sink
What tool measures volume of liquids?
Graduated Cylinder
What change turns a liquid into a gas?
Evaporation
Why do hot air balloons rise?
Warm air is less dense than cool air
Which state of matter takes the shape of its container but has a definite volume?
Liquid
If a block has a mass of 20 g and a volume of 4 cm³, what is its density?
5 g/cm³
What unit do we use for mass?
Grams (g)
What change turns a gas into a liquid?
Condensation
Why does oil float on water?
Oil is less dense than water
Which state of matter has no definite shape or volume?
Gas
What unit is commonly used for density in solids?
g/cm³
What unit do we use for volume of a solid?
Cubic centimeters (cm³)
What type of change does not create a new substance?
Physical change
What state of matter are clouds mostly made of?
Liquid droplets (not gas!)
What is the fourth state of matter found in lightning and stars?
Plasma
Two objects have the same mass, but one has a larger volume. Which has the lower density?
The one with the larger volume
How do you find the volume of an irregular object?
Use water displacement + Graduated Cylinder
What type of change creates a new substance?
Chemical change
How can scientists identify an unknown substance using density?
By comparing its density to known materials