Atoms Y9 science Flashcards
dconservation of mass
In a chemical reaction mass is neither created nor destroyed
conservation of energy
Energy is not created or destroyed but merely changes forms, going from potential to kinetic to thermal energy
Kinetic energy
energy of motion, observable as the movement of an object or subatomic particle.
Potential energy
the stored energy in an object due to its position, properties, and forces acting on it
Useful energy
the energy that goes towards the desired output of the end-use application
Element
a pure substance made of only 1 type of atom that can not be broken down further into other substances
Molecule
two or more atoms connected by chemical bonds
Compound
Compounds are substances which can be formed by chemically combining two or more elements.
chemical reaction
a process in which one or more substances, also called reactants, are converted to one or more different substances, known as products
Chemical equation
symbolic representations of chemical reactions in which the reactants and the products are expressed in terms of their respective chemical formulae.
Exothermic
a chemical reaction that releases heat, causing the temperature of the immediate surroundings to rise
Endothermic
Chemical reactions that absorb (or use) energy cooling the environment
Combustion
chemical process in which a substance reacts rapidly with oxygen and gives off heat
Products
the species formed from chemical reactions
Reactants
a substance that takes part in and undergoes change during a reaction
Greenhouse gases
gases in the earth’s atmosphere that trap heat
The enhanced greenhouse effect
extra greenhouse gases in our atmosphere trap too much of the Sun’s energy
The greenhouse effect
The greenhouse effect is the process through which heat is trapped near Earth’s surface by substances known as ‘greenhouse gases.’
Fuel
material such as coal, gas, or oil that is burned to produce heat or power
Emission
the production and discharge of something, especially gas or radiation
Fossil fuels
a generic term for non-renewable energy sources
Molecular formula
a chemical formula that gives the total number of atoms of each element present in a molecule.
Compound
a substance made from two or more different elements that have been chemically joined
Wasted energy
occurs when energy is produced but not used, or when it is used inefficiently
