Elements and Compounds

By: Elaina Allen

Element, Compound, and Chemical Formula

An element is a substance that cannot be broken down by chemical means. For example Copper, Iron, etc. A compound is a chemical species that is formed when 2 or more atoms join together chemically. For example, aluminum, hydrogen, calcium, etc. Chemical formulas are a notation that uses atomic symbols with numerical subscripts to convey the relative proportions of atoms of each element in that substance. For example, aluminum oxide= Al2O3.


What happens to element properties when it forms a compound?

When compounds are formed, the properties of the compound are different from the properties of the elements that make up the compound.

What happens to the properties if the compound separated back to the elements that formed it?

The elements regain their original properties.

How are compounds formed?

Compounds are formed from simpler substancces by chemical reactions. Some can also be formed directly from their constituent element.

How are compounds or elements separated?

They can NOT be seperated.

How do you count elements?

The elements are capitol letters and the little letters beside them are how many atoms are in each element.

Important Vocabulary

Coefficients- A numerical measure of a physical or chemical property that is a constant for a system under specified conditions. The coefficient is the number before the elements. For example, 2Mg (2 magnesium atoms).

Subscripts- They are used in writing formulas. They are a letter, symbol, or figure. For example in H2O, 2 is the subscript.