Theory Flashcards
A
X
Z
X - Chemical symbol of element
Z - Atomic number
A - Mass number
Mass number
Neutrons + Protons
Atomic number
equal to number of protons in nucleus / or number of electrons in electrically neutral atom
Electrons
- negatively charged subatomic particles
- same number as protons / atomic number
- charge = -1, relative mass = 1/2000
Protons
- positively charged subatomic particles in nucleus
- same number of electrons / atomic number
- charge = +1, relative mass = 1
Neutron
- neutral charged subatomic particle in nucleus
- mass number - atomic number
- charge = 0, relative mass = 1
Electron Configuration
2, 8, 8, 2
Isotopes
atom that have same atomic number but different mass number
Ionic compound
- when positive cation and negative anion attract each other forming a crystal lattice
Balance of Ionic compounds
Must balance overall charges and show rations between the ions
-> eg. Al Cl
2 3
Positive ion
cation, formed when metal atom loses electrons
Negative ion
anion, formed when non-metal atom gains electrons
Law of Conversation of Mass
atoms are neither created nor destroyed during a chemical reaction, they only change the way in which they are arranged
Reactants
substance that takes part in and undergoes change during a reaction
Products
substances produced at the end of the reaction