reactions Flashcards
Catalyst
A substance that speeds up a chemical reaction but are unchanged at the end (they are not reactants)
Chemical bond
Force of attraction that joins atoms together in molecules and compounds
Chemical reaction
A change where a new substance is formed by rearranging atoms and joining them together differently. A product is made at the end.
Combustion
A chemical reaction requiring heat, fuel and oxygen. It happens quickly and produces heat and light.
Conservation of mass
The mass of reactants going into a chemical reaction will be the same as the mass of the products made. This is because the number of atoms does not change.
Conserved
Can’t be created or destroyed
Decomposition
A chemical reaction that involves breaking down a compound into smaller molecules.
Endothermic reaction
A chemical reaction where energy is taken from the surroundings causing a drop in temperature. Example; photosynthesis, ice packs.
Exothermic reaction
A chemical reaction where energy is released to the surroundings causing an increase in temperature. Example; burning, hand warmers
Fossil fuel
A fuel that is made over millions of years due to the decomposition of dead organisms.
Fuel
A substance that can be burned to release energy.
non- renewable
The substance is finite (it will eventually run out).
Physical change
Changes to physical properties that don’t actually change the arrangement of atoms in compounds. Example; boiling, freezing etc…
Products
Something made at the end of a chemical reaction (right side of arrow).
Reactants
Compounds/ elements that are used/ rearranged in a chemical reaction (left side of arrow).
