Chapter 1.4 Arrangement Of Electrons Flashcards
Why do atoms bond
To gain a stable arrangement of outer shell electrons
How many electrons can S P D Hold ?
S 2
P 6
D 10
What are the 3 rules of writing electron configuration
1 lowest energy level first
2 electrons with the same spin fill the electron first
3 no single orbital can hold more than 2 electrons
Show the rise of energy In subshells
Increase in energy
1s 2s 2p 3s 3p 4s 3D 4p 4s 4d
How can you tell if the element is in s p d f block
- Looking at the last sub shell and which letter it ends at,
- identifying which sub shell the outermost electron is in
What are the factors that affect ionization energy
Nuclear charge,
The more protons there are in the nucleus the more positively charged the nucleus is and the stronger the attraction for the electron,
Distance from nucleus,
Electron close to the nucleus will be much more strongly attracted than one further away,
Shielding,
As the distance between the outer electrons and the nucleus increases so the outer electrons feel less attraction which lessens the pull of the nucleus by inner shells
Describe the trends of ionization energy In a periodic table
Ionization energy decreases down group 2
Ionization energy increases across a period
Explain why the first ionisation energy of helium is very large
Electron is not shielded from nucleus
Write the equations of first and second ionization energy:
First : x(g) = x^+(g) + e^- ,
Second : x^+(g) = x^+2(g) + e^-
Predict and explain the general trend in first ionization energy of period 3
Trend : IE increases across period 3,
Explanation : nuclear charge increases, shielding remains the same
Why does magnesium have higher ionization energy than aluminum ? (3)
Step 1 write the electronic configuration,
Mention: which element is bigger (who has more shells), shielding effect and distance from nucleus
- Al outer electron is in 3p orbital, 3p orbital has slightly more energy,
- 3p orbital has additional shielding effect given by 3s,
- Al is a bigger atom and has more energy levels,
- Electrons removed further away from the nucleus
Predict and explain the general trend in the IE when going down group 2
Trend : decreases,
Explanation: radius of the atom increases so the distance between the nucleus and outer electrons increase,
There are more filled shells between nucleus and the outer electrons,
These shield the outer electrons from the attraction of the nucleus
State and explain the trend in atomic radius of the period 3 elements
Trend : decreases,
Explanation: increasing nuclear charge,
Similar shielding effect
State the trend in the first IE in group 2
Trend: decreases
Explanation: shielding increases,
Distance between nucleus and outer electrons increase
Give one reason why the 2nd iE of silicon is lower than the 2nd IE of aluminum,
Step 1 write the electronic configuration for both and identify where the last electron is being removed from
- electron removed from 3p orbital for silicon which is further away from the nucleus so less energy required