chapter 4 Flashcards
Orbital
a region in an atom where there is high probability of fining electrons. there are s,p,d, & f orbitals. Each orbital can hold only two electrons.
an electron at a higher energy level has_____ kinetic energy & occupies a ______ orbital level
greater kinetic energy
&
higher orbital level
Periodic Law
the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements.
Period
a horizontal row of elements in the periodic table.
Group
a vertical column of elements in the periodic table.
Group 1 & 2 elements lose electrons to form _____
positive ions (CATIONs) because it brings them to the noble gas configuration in terms of shells
Group 13-17 gain electrons forming
(ANIONs) because it again brings them closer to the noble gas configuration in terms of shells
Transition metals mostly form
positive ions (cations) with a charge of 2/3+.
Atomic Number (Z)
the number of protons in the nucleus of an atom.
Mass number (A)
sum of the number of protons and neutrons in the nucleus of an atom, i.e. number of neutrons = A-Z.
Isotope
the same number of protons & a different number of neutrons.
Average Atomic mass
the weighted average of the masses of all naturally occurring isotopes of an element.
Atomic Mass Unit (amu)
a unit of mass that describes the mass of an atom or molecule. it is exactly 1/12 the mass of a carbon atom with mass number 12.
Metal
an element that is shiny, conducts heat and electricity well.
Semiconductors
not metals that are intermediate conductors of heat and electricity.
