Video narration
Your card paper is ready, with pencil, glue, and rangoli colors. Choose a color for each atom kind; real atoms aren't these colors. Draw circles, add a little glue, and fill them all alike. This is an element: only one kind of atom. For O2, touch identical circles in pairs, like matching colors grouped in a rangoli pattern. Now make H2O, water. Use one color for hydrogen and another for oxygen. Put two hydrogen circles touching one oxygen circle. Different atoms bonded in one set group make a compound. For a mixture, draw pairs of one color for N2 and another for O2. Keep each pair together, but leave the two kinds of molecules separate. They share the card without bonding to each other. Compare your three rangoli patterns: one kind of atom, different atoms bonded, or different molecules kept separate. That's what the colors and groupings show.