Atomic structure and bonding related to properties of materials Flashcards
Chemical changes and structure
Describe how elements are arranged in the Periodic Table
Elements in the Periodic Table are arranged by increasing atomic number (or increasing number of protons).
Describe the similarities of elements in the same group on the Periodic Table
Elements in the same group on the periodic table have the same valency and the same number of outer electrons, which gives them similar chemical properties.
Group 1 (Alkali Metals): Very reactive metals that readily lose one electron.
Group 7 (Halogens): Reactive non-metals that tend to gain one electron.
Group 8/0 (Noble Gases): Non-reactive (inert) gases with full outer electron shells.
Transition Metals: A group of useful metals found between Group 2 and
Group 3 on the periodic table, known for their varied oxidation states and good conductivity.
Describe the properties of a proton
Protons have a positive charge, a mass of 1 amu (atomic mass unit) and are found in the nucleus.
Describe the properties of an electron
Electrons have a negative charge, a mass of 0 amu (stating they have no mass is also accepted) and they spin around the outside of the nucleus.
Describe the properties of an electron
Electrons have a negative charge, a mass of 0 amu (stating they have no mass is also accepted) and they spin around the outside of the nucleus.
Describe the properties of a neutron
Neutrons have a neutral charge, a mass of 1 amu and are found inside the nucleus.
Calculate a neutral atom’s atomic number
Atomic number is always the same as the number of protons (it is also found on the periodic table in the data booklet).
Calculate the mass number of an element
The mass number = atomic number + no. of neutrons (no. of protons + no. of neutrons)
State the definition of an isotope
An isotope is:
one of two or more forms of the same element that have the same number of protons but a different number of neutrons
Describe a covalent bond
A covalent bond is usually between two non-metal atoms.
It is the attraction of positive nuclei for the shared pair of negatively charged electrons.
Name the 7 diatomic elements
The following 7 elements naturally occur as diatomic molecules:
Hydrogen
Nitrogen
Fluorine
Oxygen
Iodine
Chlorine
Bromine
HOFBrINCl
Describe a diatomic molecule
A diatomic molecule is a molecule composed of only two atoms.
Explain the properties of covalent molecules
They are small molecules with strong covalent bonds within the molecule and weak forces of attraction between molecules.
They have low melting and boiling points as it is the weak intermolecular forces
They cannot conduct electricity as they do not have charged particles that are free to move
They are usually insoluble
Explain the properties of covalent networks
A covalent network is one giant structure made up of very strong covalent bonds.
They have very high melting and boiling points due to only containing very strong bonds which would require a lot of energy to break.
They cannot conduct electricity (except from carbon in the form of graphite).
They are insoluble due to their larger size.
Describe how ions form
Ions are atoms that have lost or gained electrons, resulting in a charged particle.
Describe an ionic bond and structure
An ionic bond is formed between metal and non-metal ions. It is the electrostatic attraction between positively charged metal ions and negatively charged non-metal ions.
These ions arrange themselves in large ionic lattice structures - a repeating pattern of negative ions surrounded by positive ions, and positive ions surrounded by negative ions.
Explain the properties of an ionic compound
They have high melting and boiling points
They cannot conduct as a solid, the charged particles (ions) are not free to move.
Many are soluble in water
