The nearly circular path that earth takes around the sun is called

It is called an "orbit". Repeating and regular path that one object in space takes around in another one. This object ca be satellite or natural satellite like our moon. Planets, comets, asteroids and other objects in the solar system orbit the sun. Orbits come in different forms or shapes. All orbit are elliptical which means they are ellipse, similar to oval.

Alkaline earth metals are found in group 2 of the periodic table.

Efficiency is an action of doing something. for example when you take a test. good efficiency means you did well but bad effeciency or no effiency means you did bad.