chemical property

A chemical property is a characteristic of a particular substance that can be observed in a chemical reaction. Some major chemical properties include flammability, toxicity, heat of combustion, pH value, rate of radioactive decay, and chemical stability.

A chemical change or reaction is a process in which one substance changes to another substance. In this process, the characteristics of the substances change, and this is when chemical properties are observed.

A chemical property is not to be confused with a physical property, which includes such characteristics as shape (volume and size), color, texture, flexibility, density, and mass.

You can’t necessarily find out a substance’s chemical properties by looking at it. They are observed when that substance is undergoing a chemical change.

Water, for example, has a chemical structure of H₂O, or two hydrogen atoms bonded with one oxygen atom. Adding another oxygen atom gets you H₂O₂, hydrogen peroxide, which looks a lot like water both in its chemical formula and appearance in real life, but is a completely different substance.

We can drink water just fine, but you absolutely cannot drink straight hydrogen peroxide: it will chemically react with other substances in your body, damaging tissue and making you sick. That reaction (or lack thereof in the case of water) is a very basic way of telling us about the important chemical property of toxicity.

Other chemical properties include a substance’s pH value and reactivity with water and oxygen. You have to test a substance by making it undergo a reaction to find out these properties. Physical properties such as color and density, on the other hand, can be observed without making the substance undergo a chemical change.

Chemical properties helped Russian scientist Dmitri Mendeleev begin developing a periodic table of the elements in the 1860–70s. His table greatly influenced the version we use today. Mendeleev left gaps in his table, using chemical properties in part, to predict the existence of elements that would not be discovered until years later.

This video compares chemical properties and physical properties of matter:

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Who says learning isn’t yummy?! Physical and chemical property changes with S’mores! #eesrockstArs pic.twitter.com/IZ1bzFNIZm

— jessica Bates (@MrsB8sEES) March 8, 2019

@sorensensci flammability=chemical property!! @KatelynSchulze we've learned so much pic.twitter.com/NiiNf86Xmo

— Julia (@JuliaComer_) October 27, 2013

• chemical reaction 
• chemical change 
• matter 
• substance 
• pH
• physical property
• physical change

Which of the following are chemical properties?

• color
• heat of combustion
• boiling point
• melting point
• rate of radioactive decay
• density