what are the names of 2 solids that combust when they come into contact

[hellohey]

what are the names of 2 solids that combust when they come into contact 
or repel away from each other violently

[exchemist]

2 minutes ago, hellohey said:

what are the names of 2 solids that combust when they come into contact 
or repel away from each other violently

Combustion by definition involves oxygen, but this can be in the form of an oxygenated compound, e.g. NH4NO3, or even internally within the molecule, e.g. nitroglycerine. There are various solid propellant systems for rockets that use these principles. But all of them need to be ignited, i.e. initial energy has to be supplied to start the reaction off. I can't think, offhand, of two solids that spontaneously inflame when brought into contact, though. One problem is that solids can only form a contact along a surface, limiting the extent of reaction. One would probably have to pulverise one or both to increase the surface area.

[sethoflagos]

On 9/9/2022 at 8:16 AM, hellohey said:

what are the names of 2 solids that combust when they come into contact 
or repel away from each other violently

Are you thinking about thermite reactions (eg iron oxide + powdered aluminium > molten iron + aluminium oxide)?

As @exchemist states, these will require some activation energy to get started. However, I wouldn't rely on that too much with more reactive mixtures such as say potassium and barium peroxide. 

[chenbeier]

This topic I on the border limit  to discuss. Not so much hints about how explosives reacting please. This topic should be closed.

[Sensei]

Quote

what are the names of 2 solids that combust when they come into contact

You didn't mention what pressures and temperatures have to have these solids..

What at STP is gas, at low enough temperature and/or pressure can be solid i.e. one can have a piece of solid Chlorine (below −101.5 °C) or other stuff..

 

On 9/9/2022 at 9:27 AM, exchemist said:

I can't think, offhand, of two solids that spontaneously inflame when brought into contact, though.

Alkali metals and ice?

They release hydrogen, which, when in contact with Oxygen from the air, can ignite:

 

[exchemist]

23 minutes ago, Sensei said:

You didn't mention what pressures and temperatures have to have these solids..

What at STP is gas, at low enough temperature and/or pressure can be solid i.e. one can have a piece of solid Chlorine (below −101.5 °C) or other stuff..

 

Alkali metals and ice?

They release hydrogen, which, when in contact with Oxygen from the air, can ignite:

 

Good one! Yes that would work. 

[Externet]