Chemistry Flashcards
Atoms
The particles that make up all materials; the smallest part of an element that can take part in a chemical reaction
Electron shells
Also known as energy levels, the region surrounding the nucleus where electrons may be found
Electron configuration
Arrangement of electrons in electron shells
2,8,18,32
Element
A substance composed of atoms with the same atomic number; 118 are known to exist
Ground state
The lowest energy arrangement of an atom’s electrons shells
Nucleus
Heavy core at the centre of the atom, made of protons and neutrons
Electrons
Negatively charged atoms
Protons
Positively charged atoms
Neutrons
Neutrally charged atoms
How fireworks work
Modern fireworks include metal salts that colour them. Fireworks colours come from electrons changing energy levels. Heat gives electrons energy to jump from one energy level to another. They get this energy from heat which is generated when the firework is lit.
Groups
Vertical columns of the periodic table; group number is equal to the number of electrons in the outer shell of atoms of the elements in that group
Lanthanides
A special block of metallic elements with atomic numbers 58-71
Alkali metals
Group 1 elements
Alkaline earth metals
Group 2 elements
Halogens
Group 17 elements
Periods
horizontal rows of the periodic table; period number of an element is equal to the number of electron shells
Transition elements
A special block of metallic elements covering elements from groups 3-12
Nobel gases
Also known as inert gases. Group 18 elements known for their stability (lack of reactivity)
Bonds
Links that join atoms together
Covalent bonding
The sharing of electons between atoms of non-metals
Ionic bonding
Attraction of positive and negative ions formed from the transfer of electrons from metallic to non-metallic atoms
Ions
‘Charged atoms’ (or groups of atoms) formed by electrons being transferred from one atom to another
Lattices
A regular arrangement of particles.
Metallic bonding
A mutual attraction between a lattice of positive metal ions and a sea of delocalised, outer-shell electrons
Molecules
Discrete groupings of atoms covalently bonded together
Atomic number
Number of protons in an atom
