Demos explained in CER format and Labs key info

Demo #1: Nail Polish (Acetone vs. Water) Epxlain in CER format

• Claim: Acetone can dissolve nail polish, but water cannot, because acetone shares compatible intermolecular forces with the polish.

• Evidence: When applied to nail polish, the transparent acetone liquid dissolves and removes the polish from the surface, whereas the transparent water liquid leaves the polish completely intact.

• Reasoning: "Like dissolves like." Nail polish consists of non-polar and weakly polar polymers. Acetone has intermediate polarity and dipole-dipole forces that can overcome the attractive forces holding the polish together, allowing it to dissolve. Water, however, forms strong hydrogen-bonding networks with itself and cannot interact favorably enough with the non-polar polish molecules to break them apart.

Demo #2: Flame Tests & Electric Discharge Tubes

• Claim: Atoms emit specific, quantized wavelengths of light when excited because their electrons transition between discrete energy levels.

• Evidence: Heating lithium produces a red flame, copper produces a green flame, and applying electricity to a discharge tube containing neon gas causes it to glow red.

• Reasoning: Adding thermal or electrical energy excites electrons from their ground-state orbitals into higher-energy orbitals ($\Delta E = h\nu = E_2 - E_1$). When these excited electrons drop back down to lower energy levels, they release energy in the form of photons with specific wavelengths that correspond directly to the energy gap between those orbitals. Since each element has a unique arrangement of atomic energy levels, each element produces a distinct emission color.

Demo #3: Reaction of Alkali Metals with Water (Li, Na, K)

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Demo #4: Burning Sodium and Sulfur in Pure O2

• Claim: Metals form ionic oxides that are basic in water, whereas non-metals form covalent oxides that are acidic in water.

• Evidence: Burning sodium (Na) in O2 forms a solid oxide (Na2O) that turns water basic (pink indicator), while burning sulfur (S) in O2 forms a gas SO2 that turns water acidic.

• Reasoning: Sodium is a metal with low electronegativity that transfers electrons to oxygen, forming ionic Na2O containing oxide ions O2-. In water, O2- reacts to generate OH- ions, creating a basic solution. Sulfur is a non-metal that shares electrons with oxygen to form the covalent oxide SO2. When dissolved in water, SO2 forms sulfurous acid H2SO3, releasing H+ ions and creating an acidic solution

Demo #5: Breath Analyzer (Detecting Alcohol)

Demo #6: Miners' Lamp / Burning Ice CaC2 and Acetylene)