Questions

Nigeria, an African country on the Gulf of Guinea. 

Nigeria has a Federal Republic and Presidential system of Government.

The primary agent of contact metamorphism is heat or temperature.

The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness".

Here in the given options, syrup has the highest viscosity.

Helium has the lowest freezing point of all the elements. When coming to metals, mercury has the lowest freezing point of all the metals.

Federalism ::

Federalism is a system based upon democratic rules and institutions in which the power to govern is shared between national and provincial/state governments, creating what is often called a federation.

Federalism is a political concept in which a group of members are bound together with a governing representative head. 

Federalism enables the state and the national government to share power.