Vocabulary 6

solar cell: a device that generates an electric current from sunlight.

biomass conversion: getting energy from plant and animal materials by changing the into high-quality fuels.

nuclear fission: the splitting of s nucleus with a large mass into two nuclei with smaller masses.

chain reaction: a reaction that is kept going by products of the reaction.

nuclear fusion: the merging of nuclei with smaller masses into a nucleus with a larger mass.

hydroelectricity: the use of flowing water to generate electricity.

thermal pollution: the excess heating of the environment.

Vocabulary 5

thermal expansion: the expansion of matter when its temperature is raised.

pressure: the force on each unit of area of a surface.

melting: the change of a solid into a liquid.

vaporization: the change of a liquid to a gas as molecule break free from each other.

condensation: the change of a gas into a liquid as molecules attract each other.

freezing: the change of a liquid into a solid.

boiling: the formation of bubbles of vapor that escape from a liquid that is being heated.

evaporation: the vaporization of molecules from the surface of a liquid.

Vocabulary 4

Kinetic energy: the energy of a moving object.

Potential energy: energy stored in an object or material.

Temperature: the average kinetic energy of the molecules in a material.

heat: energy that flows between objects that have different temperatures.

radiation: the transfer of energy by electromagnetic waves.

conduction: the transfer of energy by direct contact of molecules.

convection: the transfer of energy by the flow of liquid or gas.

insulation: prevents heat from flowingin or out of a material.

Vocabulary 3

Compound: a chemical combination of two or more elements.

Chemical bond: a link that atoms or electrically charged particles can form with each other.

Chemical formula: a way of using letters and numbers to show how much of each element is in a substance.

Ion: an electrically charged particle with unequal numbers of protons and electrons.

Molecule: a group f bonded atoms that acts like a singular particle.

Chemical property: a way of describing how a substance changes chemically with other substances.

Exothermic: a reaction that gives up heat.

Endothermic: a reaction that absorbs heat.

Vocabulary 2

Element: a substance that cannot be broken down any further into anything simpler.

Atom: the smallest particle of an element that has the same chemical properties as the element.



 Nucleus: an atom's dense center, where most of its mass is.

Electron: a negatively charged particle that moves around an atom's nucleus.

Proton: a positively charged particle inside an atom's nucleus.

Neutron: a particle with no charge inside an atom's nucleus.

Atomic Number: the number of protons in an atom.

Metal: any of a group of elements that conduct heat and electricity, is shiny and bendable.

Vocabulary 1

Matter; any solid, liquid, or gas.

Mass: amount of matter in an object.

Volume: the amount of space an objects takes up.

Density: the amount of mass in a certein volume of material.

Physical Property: a property that can be observed without changing the identity of a substance.

Physical Change: a change in size, shape, or state without forming a new substance.

Solution: a mixture of one substance dissolved in another so that the properties ate the same throughout.

Chemical Change: a change in matter that produces a new substance with different properties from the original.