The strongest rock on Moh's scale of hardness is the diamond at 10 and the weakest rock is Talc. Anything lighter than Talc would not be considered a rock. If you want to know other rock's hardness es you'll have to look at Moh's scale of Hardness
River rock is typically a type of sedimentary rock formed through the deposition and compression of sediments over time.
Plymouth Rock is an igneous rock, specifically a glacial erratic. It is made of a type of granite called Dedham Granite.
It can be any type of rock. If heat and pressure deep in the Earth changed it, it is a metamorphic rock. If sediments of sand or other rocks compacted/cemented together, it's a sedimentary rock. If magma from a volcano cools, (on the outside of a volcano) it's an igneous rock.
No, hydrogen bonding is a relatively strong type of intermolecular force compared to other types like London dispersion forces. It is weaker than covalent and ionic bonds, but still plays a significant role in determining the properties of substances.
limestone or sandstone
The weakest type of bridge would be a board across gully.
rock(in bloodtusk ravine)
Torkoal is the weakest Fire Type Pokemon Ash has.
on outer ear
ikr
Some Idiot: steelix is the strongest rock Pokemon idiots!!! Smart guy: Steelix isn't even a rock type smart@$$, Tyranitar's the strongest =D Sand Stream doubles it's special defense and it has a huge move-pool. It's soooooo powerful, it can even compare to legendaries
pine wood
Aerogel is often considered one of the weakest materials as it is extremely lightweight and has low density. It is mostly composed of air pockets, which make it delicate and prone to breaking easily.
Hydrogen bonding between polar molecules creates the weakest bonds.
Water molecules are associated by hydrogen bonds but I suppose that these bonds are not the weakest.
vacuum