Download c) C2 Glossary Topic 1

Topic 1 Atomic Structure & the Periodic Table
Periodic Table
Chart in which the chemical are arranged in order of increasing
atomic number
Atoms
The smallest neutral part of an element that can take part in chemical
reactions
Nucleus
The positively charged centre of an atom
Protons
Positively charged subatomic particle found in the nucleus of an atom
Neutrons
Electrically neutral subatomic particle found in the nucleus of most
atoms
Electrons
Negatively charged subatomic particle found in shells around the
nucleus of an atom. An electric current in a metal wire consists of
moving electrons
Shells
The space around a nucleus that can be occupied by electrons.
Usually drawn in a circle. AKA energy levels
Energy Levels
The space around a nucleus that can be occupied by electrons.
Usually drawn in a circle. AKA shells
Relative Mass
The mass of a sub atomic particle compared to the mass of a proton
Atomic Number
The number of protons in the nucleus of an atom Also known as the
proton number
Mass Number
Total number of protons and neutrons in the nucleus of an atom. Also
known as the nucleon number
Relative Atomic
Mass
The mean / average mass of an atom relative to the mass of the
atom carbon 12 (which has the mass of 12)
Periods
Rows in the periodic table where the atomic number increases by one
across each element
Groups
A column in the periodic table – containing elements with similar
properties
Isotopes
Atoms of an element with the same number of protons & electrons
but a different number of neutrons
Relative abundance
The number of objects of a particular kind in a sample (shown as a
percentage of the total number of objects)
Electronic
Configuration
The arrangement of electrons in shells around an atom