Microscopical level

[kenny1999]

When we touch something, even lightly, is it true that some of atoms/molecules from our skin will pass into that thing while some of atoms/molecules from that thing will pass into our skin?

[StringJunky]

I don't think so. Electrostatic repulsion keeps things separate at the atomic level that aren't chemically combined. I picture the effect on the respective magnetic fields of two magnets with like polarities facing each other and trying to pushing each other away. There will be distortion in their respective fields where they meet but no crossover or penetration.

[exchemist]

2 hours ago, kenny1999 said:

When we touch something, even lightly, is it true that some of atoms/molecules from our skin will pass into that thing while some of atoms/molecules from that thing will pass into our skin?

Seeing that skin is chemically speaking a highly complex system, with many hundreds of chemical species, I think it is quite likely that a few atoms or molecules may detach and adhere to the surface of whatever we touch. Also, the water and oil in skin secretions may well dissolve a few atoms or molecules of the object we touch and transfer them to the surface of our skin. The surfaces of substances tend to be less chemically stable than the interior, due to the atoms being incompletely surrounded and thus having unsatisfied valences. So adsorption on surfaces is quite common. But as @StringJunkysays, penetration to any significant depth, i.e. more than a few atomic radii in, is likely to be zero or close to it, except in particular cases. 

[kenny1999]

As a result, so Yes or No?

For example, I don't think the skin of my finger will have any reaction with a metal object or a plastic object when I touch them, however, is there still any atoms/molecules that would transfer/jump from the surface of the object to my skin?

On 9/8/2022 at 3:57 PM, exchemist said:

Seeing that skin is chemically speaking a highly complex system, with many hundreds of chemical species, I think it is quite likely that a few atoms or molecules may detach and adhere to the surface of whatever we touch. Also, the water and oil in skin secretions may well dissolve a few atoms or molecules of the object we touch and transfer them to the surface of our skin. The surfaces of substances tend to be less chemically stable than the interior, due to the atoms being incompletely surrounded and thus having unsatisfied valences. So adsorption on surfaces is quite common. But as @StringJunkysays, penetration to any significant depth, i.e. more than a few atomic radii in, is likely to be zero or close to it, except in particular cases. 

Penetration to any significant depth? What does that mean? 

[studiot]

6 minutes ago, kenny1999 said:

As a result, so Yes or No?

Of course there are  - that is how fingerprints are produced and how you get coloured fingers if you touch wet paint.

But what is transferred, which way it is transferred and how much is transferred depends upon the nature of both your skin(how oily/sweaty it is) and the nature of the surface you touch.

Edited September 9, 2022 by studiot

[exchemist]

8 hours ago, kenny1999 said:

As a result, so Yes or No?

For example, I don't think the skin of my finger will have any reaction with a metal object or a plastic object when I touch them, however, is there still any atoms/molecules that would transfer/jump from the surface of the object to my skin?

Penetration to any significant depth? What does that mean? 

I told you that. A few atomic radii in.