1. Fill in all the gaps
isotopes
1) All substances are made up of basic units called _____________,
which are themselves made from three different element
____________________________ . elements
probability
2) In the centre of an atom is the ______________ consisting of
atomic mass
________________ charged ______________ and neutral
_____________. Moving around the _____________ are atomic number
_____________ charged _____________ in specific energy levels. sub-atomic particles
electrons
3) Particular types of atoms are called ______________ and all the electron
atoms of one type have the same number of _____________in the protons
central _____________________, which is called neutrons
the_____________________.
nucleus
4) _______________ are atoms of the same ____________(same ground state
atomic number) but with a different number of neutrons (different energy
__________________) atoms
5) An __________________ is the description of the behavior of an nucleus
________________in an atom according to quantum mechanics. It atomic orbital
represents a region in space in which the __________________ of excited state
finding electrons is highest.
positively
6) The ____________________ is the lowest energy state. To raise negatively
the atom to an___________________, energy must be added. To protons
fall back to the ground state (lowest energy), the nucleus
_________________ it had absorbed must be released
1) All elements in same _____________ have same outer shell s sublevel
_________________________. Exception is Helium which has a positive
full outer shell like Neon, but the filled sublevel is negative
an____________________
electron configurations
2) Most of the time elements in the same group have the same attraction
number of ________________________, they are involved in
valence electrons
bonding and determine the reactivity and the
_______________________ chemical properties
metals
3) The measure of the ___________________ that an atom has for
electrons involved in chemical bonds is known as nonmetals
______________________ ionization energies
4) Within a _____________, the elements with the largest atomic radii
____________________ are alkali ____________________ (the electronegativity
most electropositive elements). period
5) ____________ tend to lose electrons and form ___________ group
ions (becoming smaller ions) while ____________ tend to gain metals
electrons and form ________________ ions, (becoming larger
ions). ________________ also have high electronegativities and nonmetals
high __________________.

2. 1) In an ___________________ there is complete transference of
electrons while in a _________________ the _______________ are molecular compound
bonding by shared electrons. They both are called ______________ ionic compound
bonds.
decrease
2) If the electron is shared equally between the atoms forming a increase
covalent bond, then the bond is said to be ______________.
Usually, an electron is more attracted to one atom than to another, ionic bond
forming a ______________ covalent bond.
covalent bond
3) An _____________________ is a crystalline solid at standard conductors
temperature and pressure (STP), whereas a ___________________
can be in a solid, gas or liquid state at STP. semiconductors
insulators
4) Most of ionic compounds are _______________ in polar
solvents such as water, and covalent compounds are generally bands
________________ in water and in other polar solvents conduction band
5) In the _________________, valence and conduction bands valence band
overlap and allow a free movement of electrons. In a few elements,
weak
the ______________ are close enough to allow only a small
amount of electron excitation in an upper unoccupied band. These strong
elements are known as ____________________.
molecules
6) Most solid substances are ____________________, and in terms atoms
of the band theory of solids this implies that there is a large
forbidden gap between the energies of the soluble
___________________and the energy at which the electrons can insoluble
move freely through the material, the ___________________.
polar
7) Van der Waals forces are ______________ forces of attraction
between ______________. These forces ______________ as nonpolar
the molar mass of the molecule gets smaller and ______________
as the molar mass increases.