Elements vs. Compounds

Front

What is an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means. It consists of only one type of atom.

Front

What is a compound?

Back

A compound is a substance formed when two or more different elements are chemically bonded together. It can be broken down into simpler substances.

Front

How many elements are in the compound SLi3BaO2?

Back

4 (Silicon, Lithium, Barium, and Oxygen).

Front

How can you identify an element from its chemical symbol?

Back

An element is represented by a one or two-letter chemical symbol, with the first letter always capitalized (e.g., H for Hydrogen, He for Helium).

Front

How can you identify a compound from its chemical formula?

Back

A compound's formula contains two or more different elements (e.g., C6H12O6 for glucose).

Front

What is the chemical formula for water?

Back

H2O, which indicates it is a compound made of two hydrogen atoms and one oxygen atom.

Front

Is He3 an element or a compound?

Back

Element (Helium, represented by the symbol He).

Front

Is Na2 an element or a compound?

Back

Compound (Sodium, represented by the symbol Na, combined with itself).

Front

What does the subscript in a chemical formula indicate?

Back

The subscript indicates the number of atoms of the element in the compound (e.g., in H2O, the '2' indicates there are two hydrogen atoms).

Front

What is the difference between a molecule and a compound?

Back

A molecule is a group of two or more atoms bonded together, which can be of the same or different elements. A compound specifically refers to molecules made of different elements.