Atomic Structure Flashcards
define the term atomic number of an element?
the number of protons in the nucleus of an atom
define the term mass number of an element?
the total number of protons and neutrons in the nucleus of an atom
what is the definition of an isotope?
atoms of the same element with the same number of protons, but different numbers of neutrons
what is the relative mass of a proton?
1
what is the relative mass of a neutron?
1
what is the relative mass of an electron?
1/1840
what is the relative charge of a proton?
+1
what is the relative charge of a neutron?
0
what is the relative charge of an electron?
-1
what forces holds together protons and electrons?
electrostatic forces
what are the 4 stages of the mass spectrometer?
ionisation, acceleration, deflection + detection
write an equation to show the process that occurs when the second ionisation energy of aluminium is measured?
Al+(g) → Al2+(g) + e−
state and explain the general trend in first ionisation energies for the period 3 elements aluminium to argon?
increases
the nuclear charge increases whilst the amount of shielding remains the same
what is used to ionise a gaseous sample in a mass spectrometer
an electron gun
state and explain the difference, if any, between the chemical properties of the isotopes 113In and 115In
none
they have the same electron configuration
what is meant by the term first ionisation energy?
energy required for the removal of one electron from a gaseous atom
in a mass spectrometer, why is it necessary to ionise atoms before acceleration?
if the particles are not charged they cannot be attracted to and accelerated by a charged plate
what is adjusted in order to direct ions of different mass to charge ratio onto the detector?
the strength of the magnetic field
what is used in a mass spectrometer to accelerate the positive ions?
a charged plate
how are ions detected in a mass spectrometer?
when the positive ions collide with the detector, they accept an electron which generates an electrical current.
identify the block in the periodic table to which magnesium belongs?
s block
explain why atoms of an element may have different mass numbers?
they may have different numbers of neutrons
write an equation, including state symbols, to show the process that occurs when the first ionisation energy of rubidium is measured?
Rb(g) → Rb+(g) + e−
state the meaning of the term mass number of an isotope?
the total number of protons and neutrons in the nucleus of an atom
state the two measurements that are recorded for each isotope on the mass spectrum?
its m/z ratio and relative abundance
