ATOMIC STRUCTURE PERIODIC TABLE 1 Flashcards
What does the atomic number tell about an element?
Atomic number = number of protons in
an atom
How is mass number
calculated?
Mass number = number of protons +
number of neutron
How to calculate the number
of neutrons?
Number of neutrons = mass number -
atomic number
Define the term, isotope
Atoms of the same element with the same number of protons, different number of neutrons and therefore different mass numbers
Why do different isotopes of the same element react in the same
way
Neutrons have no impact on the chemical reactivity
Reactions involve electrons, isotopes have the same number of electrons in the same arrangement
Define relative atomic mass.
The weighted mean mass of an atom of
an element compared with one-twelfth of
the mass of an atom of carbon -12
Define relative isotopic mass
The mass of an atom of an isotope, compared with one-twelfth of the mass of an atom of carbon-12
The relative isotopic mass is
same as which number?
Mass number
What two assumptions are
made when calculating mass
number
- Contribution of the electron is neglected
- Mass of both proton and neutron is taken
as 1.0 u
How to calculate the relative
molecular mass and relative
formula mass?
Both can be calculated by adding the
relative atomic masses of each of the
atom making up the molecule or the
formula
What are the uses of mass
spectrometry?
● Identify unknown compounds
● Find the relative abundance of each isotope of an element
● Determine structural information
What does the principal quantum number indicate?
The shell occupied by the electrons
What is a shell?
A group of orbitals with the same principal quantum number
How many electrons can the
1st shell hold?
2
How many electrons can the
2nd shell hold?
8
