A third of the elements used to make a cell phone are naturally occurring.
The properties allow us to distinguish one substance from another.
Physical properties include density, color, hardness, melting and boiling points, and electrical conductivity.
Density and color can be observed without changing the physical state of the matter observed.
As matter undergoes a physical change, the melting temperature of iron or the freezing temperature of water can only be observed.
When wax is melted, when sugar is dissolved in coffee, and when steam condenses into liquid water, we can see a physical change.
Magnetizing and demagnetizing metals are examples of physical changes.
There is no change in the chemical composition of the substance in any of the examples.
Chemical properties include flammability, toxicity, acidity, reactivity, and heat of combustion.
Iron combines with oxygen in the presence of water to form rust, while chromium does not oxidize.
Neon is not a hazard because it is unreactive.
rust is a different kind of matter than iron, oxygen, and water were before it formed.
The gases produced from the explosion of nitroglycerin are very different from the original substance.
Other examples of chemical changes include reactions that are performed in a lab, all forms of burning, and food being cooked, digested, or rotting.
A gallon of milk has a larger mass and volume than a cup of milk.
The amount of matter in question affects the value of an extensive property.
An example of an intensive property is temperature.
When the gallon and cup of milk are combined, the temperature stays the same.
The properties of heat and temperature are related.
A drop of hot cooking oil spattered on your arm causes minor irritation, whereas a pot of hot oil can cause serious burns.
The drop and pot of oil are both at the same temperature, but the pot contains more heat.
The National Fire Protection Agency has a hazard diamond.
The National Fire Protection Agency developed a system to give safety information about substances.
The top diamond in the symbol specifies the level of fire hazard.
The level of health hazard is indicated by the blue diamond.
The yellow diamond is used to describe reactivity dangers, such as how quickly a substance will change chemistry.
If it is an oxidizer, which allows the substance to burn in the absence of air/oxygen, it undergoes an unusual or dangerous reaction with water, is corrosive, acidic, alkaline, a biological hazard, radioactive, and so on, and so on, and so on, and so Each hazard is rated on a scale from 0 to 4, with 0 being no hazard and 4 being extremely hazardous.
Some elements have the same physical and chemical properties.
Common behaviors can be identified by sets of elements.
Many elements conduct heat and electricity well, while others are poor conductors.
The elements can be sorted into three classes: metals, nonmetals, and metalloids.
The periodic table is a table of elements with similar properties.
As you study chemistry, you will learn more about the periodic table.