What is matter?
Matter is anything that has mass and takes up ___.
Space
A physical change does NOT create this.
A new substance
Unlike a physical change, a chemical change always creates this.
A new substance
Objects with a density GREATER than water's density do this when placed in water.
Sink
Solubility is a physical property that describes how well a substance does this in water.
Dissolves
Name the three states of matter.
Solid,Liquid,Gas
When ice melts into water, this type of change has occurred.
Physical change
Name ANY TWO of the five signs that a chemical change has occurred.
Any two of: Gas is produced, Temperature changes unexpectedly, Color changes permanently, Light or flame is produced, A precipitate (solid) forms
This is water's exact density value.
1 g/cm³
Sugar, table salt, and baking soda are all examples of this type of substance.
Soluble substances (they dissolve in water)
This state of matter has a definite shape AND a definite volume.
solid
Physical changes are usually this — meaning they can be undone
Reversible
When vinegar and baking soda are mixed, this specific gas is produced, causing bubbling.
CO₂ (Carbon Dioxide)
An apple floats in water. This tells us the apple's density is ___ than water's density.
Less (less than 1 g/cm³)
Sand, oil, and chalk are examples of substances that are this — they do NOT dissolve in water.
Insoluble
Name any THREE physical properties of matter you can observe or measure.
Any three of: Color, Texture, Mass, Volume, Temperature, Solubility
Water turns into steam (vapor) when it reaches this temperature.
212°F (100°C)
Iron turning orange-red when it rusts is an example of this sign of a chemical change.
Color change (permanent color change)
Adding this substance to water increases its density enough to make a fresh egg float.
Salt
In a solution, the substance being dissolved is the solute. The liquid doing the dissolving is called this.
The solvent
Unlike solids and liquids, gases have no definite shape OR this.
Volume
When you dissolve salt in water, you can get the salt back by doing this to the water.
Evaporating (heating) the water so it evaporates, leaving the salt behind
The vinegar + baking soda reaction is called this type of reaction because it ABSORBS energy, making the cup feel cool.
Endothermic reaction (absorbs heat)
This famous body of water is so salty (about 34% salt concentration) that people float on its surface without even trying.
The Dead Sea
To separate a mixture of sugar and sand, you dissolve it in water, filter out the sand, and then do this final step to recover the sugar.
Evaporate (heat) the water — the water evaporates away, leaving behind pure sugar crystals