Questions

Sometimes the solid particles in a liquid are very small and can pass through a filter paper. For such particles, the filtration technique cannot be used for separation. Such mixtures are separated by centrifugation.

Graphite is a good conductor of electricity as it contains free electrons to move through the structure of the graphite.

Nigeria, an African country on the Gulf of Guinea. 

Nigeria has a Federal Republic and Presidential system of Government.

IRQ-0 is the system timer commonly use in all computers. In a computer, IRQ is an interrupt request which acts as a hardware signal sent to the processor that temporarily stops a running program and allows a special program, an interrupt handler, to run instead.

A program is a group of related projects managed in a coordinated way to obtain benefits and  control  not available from managing them individually. Programs may include elements of related work outside of the scope of the discrete projects in the program.

For example:

A New car model program can be broken up into projects  for the design and upgrades of each major component (transmission, engine, interior, exterior) while the ongoing manufacturing occurs on the assembly line

Vitamins have no calories.

Silver is the best conductor of both heat and electricity among metals with a thermal conduction value of about 430 W/(mK).

Gold and copper both come respectably close to silver.

Copper being significantly less costly it is often chosen over silver in many applications.