Bundle 3: Matter Types of Reactions

Synthesis Reaction Two separate elements or molecules chemically join to form one new compound   Ex. 2H2 + O2  2H2O N2 + 3H2  2NH3 (ammonia)

Decomposition Reaction One molecule is broken into different elements or compound + element.   Ex. 2H2O2  2H2O + O2 Hydrogen peroxide CaCO3  CaO + CO2 Limestone

Combustion Reaction A substance reacts with oxygen (O2) to produce heat and light.   Ex. C + O2  CO2 C6H12O6 + O2  CO2 + H2O What substance must be present for a combustion reaction to occur? OXYGEN GAS

Exothermic Reaction An Exothermic Reaction releases heat during the reactions and does NOT require any heat to start the reaction. Heat exits the reaction No heat needed to start reaction

Exothermic reactions Exothermic – Heat is RELEASED from an object or reaction. Exo-exit-leaves Example: A Combustion Reaction is heat being released from a chemical reaction; Flaming Bubbles! Heat Out. Ex.: stored energy is released as heat, water condensation, ice freezing, hand warmers

Endothermic Reaction An Endothermic Reaction requires heat to get started and absorbs or draws in heat during the reaction. Heat to get started Heat goes INTO the reaction

Heat Transmission Endothermic – Heat goes INTO an object or reaction. Heat is absorbed. Endo-goes inside Example: Vinegar and Baking Soda is a chemical reaction that gets COLDER when mixed, ice melting, instant cold packs, Heat In.

Endo vs. Exo Endothermic – Energy of the products is greater than the reactants Exothermic – Energy of the products is less than the reactants

Fusion Fusion – the release of energy from combining two nuclei, requires high heat Fusion occurs in stars (sun) when Hydrogen atoms fuse together to form helium releasing energy

Fusion Reaction

Fission Fission – the release of energy from splitting a nucleus Fission occurs in atomic bombs, And Earth’s core, nuclear plants

Fission Reaction A nuclear reaction that occurs when a heavy atom splits into smaller atoms releasing an enormous amount of energy.

Indicate if each of the following describes A) Nuclear Fission or B) Nuclear Fusion ___ 1. a nucleus splits ___ 2. high temperature is required ___ 3. small nuclei form larger nuclei ___ 4. hydrogen nuclei react ___ 5. occurs in the sun ___ 6. large amounts of energy is released A B B B B A, B