Explanation:
A chemical property is defined as the property that brings changes in chemical composition of a substance.
For example, flammability, combustion, reactivity, electronegativity etc are allchemical properties.
On the other hand, a property that does not bring any change in chemical composition of a substance is known as a physical property.
For example, shape, size, mass, density etc are all physical properties.
Thus, we can conclude that these may all be classified as chemical properties of a substance.
Answer:
Group 18th
Explanation:
The group 18th of periodic table which is composed of Noble gases mainly was missing from the Mendeleev's periodic table. The reason for this is that Noble gases are least reactive, therefore, it was difficult to predict such elements which do not react with other elements.
I think this one is the organelles.
