EOY Exam Essential Vocab Revision - Chemistry Flashcards
Molecule
Two or more non-metals and/or hydrogen bonded together. Eg: H2O, CO2, CH4
Compund
Two or more elements bonded together. (Note: A compound can be a molecule as well and vice versa). Eg: H2O, NaCl, CuFeS2
Element
One or more of the same atom(s), each having the same amount of protons and sharing similar properties, a pure substance. Eg: Ne, F2
Atom
The building blocks of matter, the smallest particles of a chemical element.
Proton
A positively charged subatomic particle present in the nucleus of an atom. The protons have a similar atomic weight to neutrons. The protons determine the element of the atom, eg; 8 protons means the atom is an oxygen.
Electron
A negatively charged subatomic particle present in the atomic cloud of the atom, often rearranged in shells/energy levels. Electrons are about 1800th size of a proton
Neutron
Neutrons are neutrally charged subatomic particles found in the nucleus of an atom. The amount of neutrons cam affect the isotope of the element. Neutrons are about the same size of protons
Nucleus
The centre of an atom, consisting of neutrons and protons
Atomic Number
The amount of protons in an atom, which decides what element it is.
Atomic Mass
The atomic mass is the total mass of the atom, which can be found by adding up the amount of protons and neutrons. The relative atomic mass is the average weight of all the element’s isotopes, using the percentage of the isotopes present in nature
Isotope
Isotopes are the different form of an element, possessing slightly different properties, and the isotope is decided by the amount of neutrons present. Eg; Original carbon atom is called Carbon-12 (as it has an atomic mass of 12) whereas an isotope of carbon is called Carbon-14 (as there are two extra neutrons, increasing the atomic weight to 14)
Electron Shells
Sometimes referred to as energy levels, are shell(s) that are arranged and hold certain amount of electron(s).
Metals and their properties
Mostly found in the left side of the periodic table. Elements that have certain properties, such as:
* Good conductors of heat and electricity
* Posses a high Melting Point and Boiling Point
* Usually posses lustre (shine)
* Ductile (Able to be drawn out into a wire)
* Malleable (Able to be beaten up, bent or flattened into shape)
* Mostly found in a solid state
Non-Metals and their properties
Mostly found towards the right end of the periodic table. Elements that do not posses properties of metals.
Metaloids
Elements that contain features from both metals and non-metals. Examples include; Boron, silicon, germanium, etc.
Noble gasses
Non reactive elements that posses a full valence shell. Found in Group 8. Examples include; Helium, Neon, Argon, Krypton, xenon, etc
Halogens
Reactive non-metals found in Group 7. Examples include; Fluroine, Chlorine, Bromine, Iodine, etc.
Groups and what they tell you
In a periodic table
Columns in the periodic table. Elements in a group have similar properties. The group number tells you the amount of valence electrons.
Period and what they tell you
Rows found in the periodic table. Periods tell you have many shells the elements posses
Alloy
A metal formed by bonding together one or more metals together, or bonding between metals and non-metals. The new substance formed has different properties.
Chemical Bonding
Elements bonded together through either metallic, ionic or covalent bonding.
Lattice
referring to chemically bonded compunds
The pattern or structure of a bonded compound to form crystal like structures.
Chemical Formula
A small, shortened way of writing a chemical’s name using symbols of elements and subscripted numbers to represent the number of atoms for the element. Eg; The chemical formula for water (dihydrogen monoxide) is H2O