Atomic structure Flashcards
what do the chemical properties of elements depend on?
Their atomic structure and electron arrangement
list the fundamental particles in an atom
Protons, neutrons and electrons
state the relative charges of each fundamental particle
- Proton = +1
- Neutron = 0
- Electron = -1
state the relative mass of each fundamental particle
- Proton = 1
- Neutron = 1
- Electron = 1/1836
Explain the relative mass of electrons
Electron mass is negligible
how do you calculate the number of neutrons
neutron = mass number - proton munber
define mass number
Mass number is the total sum of protons and neutrons in an atom
what does (+) and (-) mean on an element
+ means loss of electrons
- means gaining of electrons
list two discoveries from the gold foil experiment
- Atoms are mainly empty space
- Atoms have a small positive nucleus
State two differences between the plum pudding model and atomic structure today
- The nucleus contains both protons and neutrons
- Electrons are in orbitals
What is an isotope and why do all isotopes have the same chemical properties?
An isotope is an element with the same atomic number but different mass numbers. They have the same chemical properties due to the same electronic configuration
A mass number of an element should be written to how many decimal places?
One decimal place
State two elements exempted from the trend of electronic configurations in transition metals
Chromium and copper
write the electronic configuration for chromium
1s2 2s2 2p6 3s2 3p6 4s1 3d5
write the shorthand electronic configuration for scandium
[Ar] 4s2 3d1
What is the rule for transition metals when charged
Start removing electrons from 4s orbital because it the highest
Define ionization energy
The amount of energy required to remove one mole of an electron from one mole of an atom in its gaseous state
State 3 factors affecting ionization energies
- Atomic radius
- Electron shielding
- Number of protons (Nuclear charge)
Define atomic radius in terms of ionization energies
- The further away from the nucleus, the weaker the attraction for the outermost electron
Define number of protons in terms of ionization energies
The higher the nuclear charge (with an increasing number of protons) the greater the attraction
Define electron shielding
The repulsion of inner shells of electrons
Describe the trend of electron shielding
shielding remains constant across the period and increases down the group