## Atomic, Covalent, and Ionic Radius

megan blatt 2B
Posts: 61
Joined: Fri Sep 28, 2018 12:28 am

### Atomic, Covalent, and Ionic Radius

During lecture, Dr. Lavelle went over atomic, covalent, and ionic radius. I know that the definition of covalent and atomic radii are the same so I was wondering what the difference between the two are? Also is the definition for how to find the ionic radius the same as covalent and atomic? Lastly, are these radii essentially an average since you half the distance between centers of neighboring atoms even if the two atoms aren't the same element? If somebody could please clarify this concept for me, that would be amazing!

Manya Bali 4E
Posts: 66
Joined: Fri Sep 28, 2018 12:23 am

### Re: Atomic, Covalent, and Ionic Radius

So I believe atomic radius is just referring to the radius of a single atom at a time. Covalent radii refers to the radius of the two atoms involved in the covalent bond and can be found, as you say, essentially by taking the average (or dividing in half the distance between the two atoms' nuclei) if the atoms are the same. I'm not sure if the same can be said when the atoms are different. Ionic radii are more complicated since there is usually a small cation and large anion involved. I think the most important thing to take away from all of this is that all of these radii typically follow the same periodic trends.

Carlos De La Torre 2L
Posts: 60
Joined: Tue Oct 09, 2018 12:16 am

### Re: Atomic, Covalent, and Ionic Radius

I think Covalent and Ionic Radii is the distance between the center of two atoms halved so if you look at the distance between the center of two atoms bonded together and halve it, it should be the covalent or ionic radii (depending on the bond between the atoms.

haleyervin7
Posts: 61
Joined: Fri Sep 28, 2018 12:15 am

### Re: Atomic, Covalent, and Ionic Radius

How will we know if something is ionically or covalently bonded?

Katie_Duong_1D
Posts: 69
Joined: Fri Sep 28, 2018 12:27 am

### Re: Atomic, Covalent, and Ionic Radius

Hi Haley!

An ionic bond is between a cation (nonmetals) and an anion (metals). Positive and negative ions attract each other and form an ionic bond; nonmetals are stronger and get electrons from the metal.

A covalent bond is between two electromagnetically similar nonmetals. Neither nonmetal is stronger than the other and they share electrons in the outer orbitals to achieve stability.

Katelyn Phan 2A
Posts: 61
Joined: Fri Sep 28, 2018 12:23 am

### Re: Atomic, Covalent, and Ionic Radius

haleyervin7 wrote:How will we know if something is ionically or covalently bonded?

In a covelant bond, you would share electrons. This often occurs between two non-metals due to their high ionization energy.
On the other, ionic bonds are between a metal and a nonmetal where there is a transfer of electrons instead.