Which of the following metal carbides is known as a methanide?

The basis of the quantum mechanical model of an atom is

If $\vec{a}, \vec{b}, \vec{c}$ are non-coplanar vectors and $\lambda$ is a real number,then the vectors $\vec{a}+2 \vec{b}+3 \vec{c}$,$\lambda \vec{b}+4 \vec{c}$,and $(2 \lambda-1) \vec{c}$ are non-coplanar for:

$A$ line with positive direction cosines passes through the point $P(2,-1,2)$ and makes equal angles with the coordinate axes. The line meets the plane $2x+y+z=9$ at point $Q$. The length of the line segment $PQ$ equals

Companion cells are closely associated with $..........$.

$A$ body of weight $64 ~N$ is pushed with just enough force to start it moving across a horizontal floor and the same force continues to act afterwards. If the coefficients of static and dynamic friction are $0.6$ and $0.4$ respectively,the acceleration of the body is (Acceleration due to gravity $= g$)