Element,Compound, Chemical Formulas

By: Prishmi Nagarajan

What is an Element? What is a Compound? What are Chemical Formulas?

Elements: A element is a pure substance that can’t be separated into simpler substances. Elements are arranged on the periodic table by atomic number (number of protons).

Examples: Gold, iron, and platinum

Compounds: Two or more elements that are chemically combined when elements become a compound, they lose their characteristic elemental properties. The properties of a compound are not the same as the element that forms it. If the compound separates back into the elements that they were, they regain their properties. Compounds are formed when two or more elements are chemically combined. Compounds can only be separated by a chemical reaction. Elements can’t be separated.

Examples: CaCl, H2O, and NaHCO3

Chemical Formulas: It is a notation that uses atomic symbols with numerical subscripts to convey the relation proportions of atoms of each element in that substance.

You determine how many elements are in a chemical formula by seeing how many capital letters are in the equation. The number of atoms is in the bottom right hand corner on each element. If there is not a number there, then it is understood to be one. You add up the numbers to get your total number of atoms.

Similarities and Differences between Compounds and Elements

· Compounds can be broken down and elements can not.

· An element is represented using symbols, but a compound is represented using a formula.

· They both are substances that can’s physically separated

· They are both made up of atoms

What are Coefficients? What are Subscripts?

Coefficients: The number of molecules of reactant or products.

Example: Combustion of hydrogen, forming water

Subscripts: They indicate the ratio of elements

Example: H2O