1.2 Flashcards
What is an orbital
A place where there’s high probability of finding an electron
What is the maximum amount of electrons in each sub shell?
s-2
p-6
d-10
What is the rule regarding 4s?
electrons enter 4s before 3d, and leave 4s before 3d
What are the exceptions of the 4s rule?
Chromium and Copper
What is the first molar ionisation energy?
The energy needed to remove one mole of outer electrons from one mole of gaseous atoms
What are the 3 factors that affect ionisation energy?
-Distance from nucleus
-Nuclear charge (proton number)
-Inner electron shielding
Whats the trend for ionisation energy down a group?
Going down, decreases as there is more shielding and less effective nuclear force
What is the trend for ionisation energy going across a period?
Generally increases, as nuclear charge increases
Explain the group 2 to 3 discontinuity (Be, B)
-Be outermost electron is on s shell
-B outermost electron is p shell
-B outermost electron is easier to remove because it’s further from nucleus
Explain the group 5 to 6 discontinuity (N, O)
-Both have the most outermost electron in the p shell, on same energy level
-Because of repulsion, its easier to remove one of Oxygens paired electrons
Explain Alpha decay
- Nucleus emits 2 protons and 2 neutrons
-Atomic number goes down by 2
-Atomic mass goes down by 4
-Can be stopped by a few cm of air or a piece of paper
Explain Beta- decay
-An electron is emitted from the nucleus
-Neutron turns into proton
-Atomic number increases
-Mass number stays the same
-Stopped by 5mm of Al or a few metres of air
Explain Beta+ decay (positron emission)
-Proton turns into neutron and a positron
-Positron is emitted from nucleus
-Mass number stays same
-Atomic number decreases
Explain electron capture
-Occurs in proton rich atoms, outer shell electron is drawn into nucleus and combines with proton, making a neutron
-Mass number remains same
-Atom number drops by one
Explain gamma emission
-No particle is emitted and nucleus does not change
-Can be stopped by 10cm of lead, 1m of concrete, or a few km of air
How do alpha particles act in an electric field?
-They are positive, heavy, slow moving
-Attracted to negative plate (cathode)
How do Beta- particles act in an electric field?
-Light and fast moving
-Attracted to positive plate (anode)
How does gamma radiation act in an electric field?
Uncharged, therefore unaffected
What is the relationship between frequency and energy?
Directly proportional
In the balmer series, what energy level do photons relax to?
the second
What are the two equations for energy change?
E=hf
E= hc/lambda
What energy levels do photons relax to in the Lyman series?
The first
What is the convergence limit?
The frequency at which the difference in frequency between successive lines is zero
