February 27

Endothermic vs. Exothermic Reactions 🔥❄️

📅 Lesson Overview:
Today, we learned about how energy is transferred during chemical reactions and the difference between endothermic and exothermic reactions through a guided note-taking session.

📝 Key Concepts Covered:

1️⃣ Conservation of Energy

• According to the Law of Conservation of Energy, energy cannot be created or destroyed—it can only transfer or transform.

• All chemical reactions involve energy changes as bonds break and form.

2️⃣ Energy Transfer in Reactions

• When bonds break, chemical energy is released and transferred to form new bonds.

• Some of this energy is used to create new products.

3️⃣ Energy Transformations

• Chemical energy can convert into thermal, light, or sound energy.

• This explains why some reactions give off heat or light (like combustion) and why others absorb heat (like ice packs).

🔥 Exothermic Reactions (Release Energy)

• "Exo" means outside, meaning these reactions release energy into the surroundings.

• The temperature of the surroundings increases (it feels warm/hot).

• Example: Burning wood, fireworks, and hand warmers.

❄️ Endothermic Reactions (Absorb Energy)

• "Endo" means within, meaning these reactions absorb energy from the surroundings.

• The temperature of the surroundings decreases (it feels cold).

• Example: Melting ice, cooking food, and instant cold packs.

🌍 Why This Matters:

Understanding energy transfer in reactions helps explain how everyday chemical changes work—from the heat in a campfire to the cooling effect of sweat!

✅ Great job working through these concepts today! Keep reviewing your notes and examples to prepare for upcoming activities. ⚡🧪