C1, C2 & C3 Glossary of terms Flashcards
What is a molecule?
A small group of atoms covalently bonded
What is an aqueous solution?
the mixture made by adding a soluble substance to water
What is an atom?
the smallest part of an element that can still be recognised as that element; consisting of a central nucleus containing protons and neutrons and energy levels with shells.
Define atomic number.
the number of protons (which equals the number of electrons) in an atom. It is sometimes called the proton number
What is a compound?
a substance made when two or more elements are chemically bonded together
What is an electron?
a tiny particle with a relative charge of -1 and a mass of 1/2000 amu. Electrons orbit the nucleus of atoms or ions in shells.
What is the electronic structure?
a set of numbers to show the arrangement of electrons in their shells (or energy levels)
Define the word element.
a substance made up of only one type of atom. An element cannot be broken down chemically into any
simpler substance
What is a group?
all the elements in the columns (labelled 1 to 7 and 0) in the periodic table
What is an ion?
a charged particle produced by the loss or gain of electrons
Define 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
State the law of conservation of mass.
the total mass of the products formed in a reaction is equal to the total mass of the reactants
What is mass number?
the number of protons plus neutrons in the nucleus of an atom
What is a neutron?
a dense particle found in the nucleus of an atom. It is electrically neutral, carrying no charge
What are noble gases?
the very unreactive gases found in Group 0 of the periodic table. Their atoms have very stable electronic structures due to a full valence (outer) shell (energy level).
What is the nucleus (of an atom)?
the very small and dense central part of an atom that contains protons and neutrons
What is the periodic table?
an arrangement of elements in the order of their atomic numbers, forming groups and periods
What is the product in chemistry?
a substance made as a result of a chemical reaction
What is a proton?
a tiny positive particle found inside the nucleus of an atom with a relative charge of +1
What is the reactant in chemistry?
a substance we start with before a chemical reaction takes place
What is a shell/energy level?
an area in an atom, around its nucleus, where electrons are found
What is a state symbol?
the abbreviations used in balanced symbol equations to show if reactants and products are solid (s), liquid (l), gas (g) or dissolved in water (aq)
What is a 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
What is a word equation?
a way of describing what happens in a chemical reaction by showing the names of all reactants and the products they form
