First Test Flashcards
aqueous solution
the mixture made by adding a soluble substance to water
Atom
the smallest part of an element
atomic number
the number of protons (which equals the number of electrons) in an atom.
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 shell
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
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
nucleus (of an atom)
the very small and dense central part of an atom that contains protons and neutrons
product
a substance made as a result of a chemical reaction
proton
a tiny positive particle found inside the nucleus of an atom
reactant
a substance we start with before a chemical reaction takes place
shell
an area in an atom, around its nucleus, where electrons are found
symbol equation
an equation that helps you see how much of each substance is involved in a chemical reaction by showing the chemical symbols and formulae of all the reactants and products involved
