Questions

Free memory is maintained in linked lists, each of equal sized blocks. Any such block is of size 2^k. When some memory is required by a process, the block size of next higher order is chosen, and broken into two. Note that the two such pieces differ in address only in their kth bit. Such pieces are called buddies. When any used block is freed, the OS checks to see if its buddy is also free. If so, it is rejoined, and put into the original free-block linked-list.

Yes, future is always infront of us, but no one can see it.

"Pressure" is the ratio of mass to area. So, for any given area, the one with more mass pressing on it will experience a higher pressure.

As you go more deeply into the atmosphere OR earth itself, you are putting more and more mass over you. For the same unit area therefore, the pressure, (mass/area) increases.

Hence, the lowest layer will always have the highest pressure i.e, inner core.

Steel is not a compound or element. Steel is an alloy of iron and carbon and other elements and hence it is a mixture. Because of its high tensile strength and low cost, it is a major component used in buildings, infrastructure, tools, ships, automobiles, machines, appliances, and weapons.