Atomic structure and radiation chemistry Flashcards
Refer to the number of valance electrons in an atom.
Groups (vertical columns)
Electrons on the outermost shell.
Valance electrons
16O, 17O and 18O
Three stable isotopes of oxygen
Tells you how many shells an element has.
Horizontal row
Atoms that tend to give away electrons to other atoms.
- groups I, II and III
Electropositive
Electron greedy, tend to pull electrons from other elements.
- groups V, VI and VII
Electronegative
When the valance shell is full, the element is stable and is :
Not reactive
When the valance shell is incomplete, the element is:
Reactive - it wants to donate, receive or share electrons with other elements.
These are located on the far right of the periodic table of elements and have full outer electron shells (not reactive).
Nobel gases
Matter can neither be created nor destroyed.
Law of conservation of energy
- Covalent bonding
- 1 or more different atoms.
- Usually smaller
- Always covalent bonding
- Same or different types of atoms involved
Molecules
- Can be ionic or covalent bonding
- Must always be two different atoms involved.
Compounds
Involve the attraction of opposite electrical charges.
- One atom donates an electron to another atom, making both atoms ions.
- The opposite charges created become attracted to one another
- Molecules composed of these are most stable as crystals.
Ionic bonds
Elements that have an electrical charge.
- By either gaining or losing electrons
Ions
Positively charged ions.
Cations
Negatively charged ions.
Anions
Form between two atoms when they share electrons.
- number of electrons shared varies depending on how many the atom needs to fill its outermost electron shell.
- Stronger than ionic bonds.
Covalent bonds
Equal sharing of electrons.
- Hydrophobic
Non-polar covalent bonds
Unequal sharing of electrons.
- Hydrophilic
- The nucleus that spends more time with the electron will have a partial negative charge, the one spending less time has a positive partial charge.
- High electronegativity = more likely to form this kind of bond.
Polar Covalent bonds
Shorthand representation of the full name of an element.
Symbols
A group of ions that function as a single like a single atom.
- do not split them up
Polyatomic ions
Represent the number of atoms in the molecule in the formula.
- when there is no number, assume it is 1.
Subscript
Represents the charge of an atom in a formula.
Superscript
Help keep track of electrons that are lost or gained.
- The sum of these in a compound is 0.
- The sum of these in polyatomic ions is equal to the charge of the ion.
Oxidation numbers
Elements that have two oxidation numbers. (especially true for transition metals)
Bivalent
Determined by adding up the atomic mass of each atom in the formula.
Molecular mass (formula weight)
In a compound containing a metal and polyatomic ion, this is named first, and then this is named second.
The metal is named first, the polyatomic ion is second.
In a compound containing a metal and one other non metal, this is named first, and then this is named second and given the suffix -ide.
The metal is first, the non-metal is second and given the suffix -ide
Usually in the case of oxides, this number will influence the naming of the compound.
- Number prefix + name of the 1st element (usually the metal) + number prefix of the second element + ide suffix.
The subscript number.
This suffix is used for the bivalent compound with the lower oxidation number.
Ous
This suffix is used for the bivalent compound with the higher oxidation number.
-Ic
copper is changed to this when naming for the high or low number.
Cupr - ous or ic
Iron is changed to this when naming for the high or low number.
Ferrous or ferroic
- Cu (copper) +1 or +2
- Hg (mercury) +1 or +2
- Fe (iron) +2 or +3
Bivalent elements
When atoms or molecules interact to form new molecules.
Chemical reaction
The abbreviation for the chemical change.
Chemical equations
The process of building or breaking chemical bonds.
Chemical reactions
The forming of a new compound from two or more reactants.
Synthesis equations
Represent reactions where a compound is broken down into the simpler parts that made it.
Decomposition equations
1 ionic compound and 1 element are mixed together.
- The element will replace an ion in the ionic compound and release the other ion.
- If the element is + charged, it will replace the cation, if it is - charged, it will replace the anion.
- Results in two new compounds.
Single replacement reactions
Represent neutralization (as in acids and bases) and hydrolysis. - Two compounds as reactants and two different compounds as products when you are done.
Double replacement reactions (metathesis)
Nuclear change, the decay in the nucleus of an atom.
Radioactivity
Two protons and two neutrons decaying from the nucleus of an atom.
- Stopped by a piece of paper.
Alpha Radiation
An electron is emitted or a positron is emitted.
- Stopped by a thin sheet of metal.
Beta radiation
Usually emitted during alpha or beta decay (as wavelengths)
- Most damaging, requires thick lead to stop it.
Gamma rays
The amount of time that it takes for half of the initial amount of radioactive material to decay
- The longer this is, the more stable the radioactive compound is- meaning it hangs around longer.
Half Life
The result of building or breaking chemical bonds.
- The end result of a reaction.
Product
Atoms or molecules that will interact.
Reactant
Carries enough energy to ionize or rip electrons from an atom.
- Shorter wavelength and higher in energy.
Ionizing radiation
The process of making an ion. (donating or receiving electrons).
Ionization
- Time
- Distance
- Shielding
Protecting yourself from radiation
