## Ionization energy

Viviana Velasquez
Posts: 97
Joined: Sat Jul 20, 2019 12:15 am

### Ionization energy

Are we expected to know a specific formula for ionization energy or only the general trends of ionization energy?

Kyla Grunden 1L
Posts: 46
Joined: Sat Sep 07, 2019 12:16 am

### Re: Ionization energy

I think we should know the general trends for ionization energy, not only because he went over it in class but because it's useful for drawing Lewis structures and understanding other topics.

Ionization energy increases as you move across a period and decreases as you move down groups.

805373590
Posts: 101
Joined: Wed Sep 11, 2019 12:17 am

### Ionization energy

Can someone please explain how ionization energy measured

Kendall 3H
Posts: 52
Joined: Wed Sep 18, 2019 12:18 am

### Re: Ionization energy

Ionization energy is defined as the minimum amount of energy required to remove the most loosely bound electron from an atom or molecule in gas state. The tighter a molecules radius, the harder to remove an electron from it. Thats how I like to think of it. So as atomic radius increases, ionization energy decreases.

Drake Choi_1I
Posts: 58
Joined: Sat Aug 17, 2019 12:15 am

### Re: Ionization energy

The atomic radius generally increases from right to left across a group. It also normally increases top to bottom within a group. I use the periodic table and the inverse relationship between atomic radius and ionization energy to help with ionization energy problems.

Kaitlyn Jang 1F
Posts: 45
Joined: Sat Aug 17, 2019 12:16 am

### Re: Ionization energy

I think you should know that on the periodic table, ionization energy increases going left to right across a period because atomic radius decreases, so electrons are more closely attracted to the nucleus. Going down a group, ionization energy decreases because valence electrons are shielded further away from the nucleus.

preyasikumar_2L
Posts: 101
Joined: Fri Aug 09, 2019 12:17 am

### Re: Ionization energy

It's pretty important to understand the ionization energy trends when looking at a periodic table - ionization energy increases from left to right across a period and decreases move down groups. It is measured in joules (J) or electron volts (eV), and is calculated by subtracting 1 from the atomic number, squaring that value, and multiplying the result by 13.6 (you get the answer in eV).

Ionization energy (of an atom, in eV) = (atomic # - 1)2 x 13.6
Ex: Ionization energy of He = (2-1)2 x 13.6 = 13.6 eV

Anna Chen 1K
Posts: 104
Joined: Thu Jul 25, 2019 12:18 am

### Re: Ionization energy

You should understand the trends of ionization energy. It increases going across a period and up a group.

chrisleung-2J
Posts: 112
Joined: Fri Aug 09, 2019 12:17 am
Been upvoted: 1 time

### Re: Ionization energy

I'm not sure if we'll get into it during this course, but there are some exceptions to the general trend. For example, the elements in group 16 tend to have lower 1st ionization energies than the elements in group 15 due to the fact that group 16 elements have a filled orbital which leads to greater interelectronic repulsions between the two electrons in it.

rohun2H
Posts: 100
Joined: Wed Sep 18, 2019 12:19 am

### Re: Ionization energy

Ionization energy is also important when drawing lewis structures as the atom with the lowest ionization energy is typically drawn as the central atom.

Lauren Stack 1C
Posts: 100
Joined: Sat Aug 17, 2019 12:18 am

### Re: Ionization energy

I believe that it is most important to understand the general trends associated with ionization energy. Ionization energy is said to be the energy needed to remove an electron from an atom in the gas phase. Thus, ionization energy decreases down a group and increases across a period.

Abigail_Hagen2G
Posts: 107
Joined: Fri Aug 09, 2019 12:17 am

### Re: Ionization energy

All you're really supposed to know for Ionization Energies is the trends for lewis structures later.

Emil Velasco 1H
Posts: 96
Joined: Wed Nov 21, 2018 12:19 am

### Re: Ionization energy

I don't think we have to know the actual equation but rather just the general trend of Ionization Energy in the periodic table.