Elements and Molecules

Atoms, Elements, Molecules, Compounds

Objective:

Distinguish between atoms, elements, molecules, and compounds.

​If this meterstick was an human cell, then an atom is one tiny millimeter

​READ ONLY!

When deciding if something is an element or a compound:

Count the number of capital (large) letters.

Atoms

​Compounds

• C

• O_{2 write these examples}

• Na

• Co

• CO

• LiI

• NaCl

​Notice you have CO and Co. The size of the O represents two completely different substances.

One is an element and one a compound

​Very important: each element has only one CAPITAL letter. The HG is actually written wrong. Ne is correct.

​A lot to write but important!

​*

​Everything on here
is an element!

Multiple Choice

Which substance is not an element?

• Neon (Ne)

• Oxygen (O₂)

• Carbon dioxide (CO₂)

• Iron (Fe)

​

​Soap-- C₁₇H₃₅CO₂Na

Multiple Choice

Which substance is a compound?

• Neon (Ne)

• Oxygen (O₂)

• Carbon Dioxide (CO₂)

• Nitrogen (N₂)

Multiple Choice

Which substance is not a molecule?

• Neon (Ne)

• Oxygen (O₂)

• Carbon Dioxide (CO₂)

• Nitrogen (N₂)

Multiple Choice

Is Sodium (Na) an element or a compound?

• Element

• Compound

Multiple Choice

Is Sodium Chloride (NaCl) an element or compound?

• Element

• Compound

Multiple Choice

Is Iron (Fe) an atom or a molecule?

• Atom

• Molecule

Multiple Choice

Is Chlorine (Cl₂) an atom or a molecule?

• Atom

• Molecule

Multiple Choice

A molecule differs from a compound.

• A molecule is always has two or more different elements.

• A compound can be two or more of the same element or more than one element together.

• They are exactly the same.

• A compound is always has two or more different elements.