2.1- Useful Reactions
This everyday reaction combines oxygen with a fuel, like wood or natural gas, and produces heat, light, carbon dioxide, and water.
Combustion
This is the most obvious sign of a chemical reaction — like when wood burns or fireworks explode.
color change or production of light/heat
This gas is required for all combustion reactions.
Oxygen
Melting ice is an example of this type of reaction, because heat from the surroundings is absorbed.
Endothermic
The blue whale, the largest animal on Earth, feeds mainly on these tiny shrimp-like creatures.
Krill
This reaction allows plants to convert carbon dioxide and water into glucose and oxygen using sunlight.
Photosynthesis
When vinegar and baking soda mix, this type of change happens as bubbles appear.
gas formation
Combustion of fuels like gasoline always produces these two products.
Carbon dioxide and water
A burning candle is an example of this type of reaction because it releases heat and light.
Exothermic
This bird is famous for being able to mimic human speech.
Parrot
This gas makes baked goods rise when baking soda reacts with an acid such as vinegar or lemon juice.
Carbon dioxide
In some reactions, a solid forms and sinks out of a solution — this solid is called a ____.
precipitate
This type of reaction occurs when an acid and a base combine to form water and a salt.
Neutralization
This process in both plants and animals breaks down glucose with oxygen to release energy.
Cellular respiration
Sharks don’t have bones — instead, their skeletons are made of this material.
Cartilage
This chemical is often added to swimming pools to kill bacteria through a disinfecting reaction.
Chlorine
In an exothermic reaction, this type of energy change is released to the surroundings.
heat (thermal energy)
When stomach acid (HCl) causes heartburn, taking an antacid works because it contains this type of substance.
base
This process in plants uses sunlight to turn carbon dioxide and water into glucose and oxygen.
Photosynthesis
This desert animal can survive for weeks without water by storing fat in its hump.
Camel
When you take an antacid tablet, this gas is released as the base neutralizes stomach acid.
Carbon dioxide
In an endothermic reaction, energy must be absorbed to break bonds. This is why a cold pack feels ____ when activated.
colder
Fire needs three things to keep burning: fuel, heat, and this.
Oxygen
Melting ice is an example of this type of reaction, because heat from the surroundings is absorbed.
Endothermic
Kangaroos, koalas, and opossums carry their young in pouches. They belong to this group of mammals.
Marsupials