Elements , Compounds And Mixtures Flashcards
What is an element
An element is a substance that cannot be broken down into simpler substances by any physical or ordinary chemical means. It may exist independently or combine with other elements to make many types of substances.
What is a compund?
A compound is a stance made up of two or more elements. The elements in ompound are chemically combined in a fixed ratio.
What us a mixture?
Substances that are not pure are called mixtures
State the characteristics of a compound.
The characteristics of a compound are:
•it is made up of two or more elements
• it will always have the same elements combined in a fixes ratio
•a compound is always homogeneous
•they are identical and have the same properties throughout
•the properties of a compound are different from those of its element
State the characteristics of mixtures
A mixture consists of molecules of two or more substances (elements, compounds, or both) in any proportion such that hey do not undergo any chemical change.
The constituents if a mixture may br present in any ratio or proportion
A mixture does not have any property of its own
A mixture does not have a fixed meliting or boiling point
The formation of a mixture does not involve the exchange if energy
The constituents of a mixture can be separated by physical means
What us a homogeneous mixture
homogeneous if its constituents are uniformly mixed and has the same properties throughout.
What is a heterogeneous mixture
A mixture is said to be
Heterogeneous cous if its constituents are not uniformly mixed and it does not have the same properties throughout.
What is sublimation
The change of a solid directly into its vapour state without passing through the liquid state is called sumblimatiom
