Key Words!๐ข๐ข๐ข Flashcards
aqueous solution
the mixture made by adding a soluble substance to water
atom
the smallest part of an element that can still be recognised as that element
atomic number
the number of protons (which equals the number of electrons) in an atom. It is sometimes called the proton number
balanced symbol equation
a symbol equation in which there are equal numbers of each type of atom on either side of the equation
compound
a substance made when two or more elements are chemically bonded together
electron
a tiny particle with a negative charge. Electrons orbit the nucleus of atoms or ions in shells
electronic structure
a set of numbers to show the arrangement of electrons in their shells (or energy levels)
element
a substance made up of only one type of atom. An element cannot be broken down chemically into any simpler substance
group
all the elements in the columns (labelled 1 to 7 and 0) in the periodic table
ion
a charged particle produced by the loss or gain of electrons
isotope
atoms that have the same number of protons but different number of neutrons, i.e., they have the same atomic number but different mass numbers
law of conservation of mass
the total mass of the products formed in a reaction is equal to the total mass of the reactants
mass number
the number of protons plus neutrons in the nucleus of an atom
neutron
a dense particle found in the nucleus of an atom. It is electrically neutral, carrying no charge
noble gases
the very unreactive gases found in Group 0 of the periodic table. Their atoms have very stable electronic structures