ATOMS and MOLECULES

WHAT ARE ATOMS?

• ATOM is the smallest part of the matter. 
• Atoms are made up of: PROTONS, NEUTRONS and ELECTRONS.
• Protons and neutrons are in the NUCLEUS and electrons are around the nucleus distributed in SHELLS.
• Atoms always have the same number of protons and electrons.
• MOLECULE is made up of atoms.

MAKING MOLECULES WITH ATOMS

• ELEMENTS in the same group have similar chemical and physical properties.
• VALENCE NUMBER is the number of electrons in an atom's outer shell.

MOLECULES IN MOTION

• TEMPERATURE is the measure of molecular movement.