Very small particles decelerate rapidly when hitting the atmosphere and are structurally robust enough that they just filter down through the air as meteoritic dust. Really big objects - think house size and above, are so massive in comparison to their surface area that they hardly decelerate at all and hit with their original velocity.
For objects between these sizes all sorts of things can happen. generally, the smaller and denser the object the more likely it is to reach the surface; however, relatively large (several metres across) stony meteorites (or the bizarre carbonaceous chondrites) tend to disintegrate through deceleration in the upper atmosphere and very little survives to hit the ground, or what lands is a shower of fragments.T =he vast majority of meteorites are made from stone, however, almost all the largest meteorites are made from structurally resilient iron/nickel.
There's been quite a lot of excitement recently caused by the release of classified data showing that relatively large objects are ploughing into the upper atmosphere and exploding on a quite regular basis. And when I say exploding - I mean think multi kiloton explosions: