When a small amount of impurity atoms are added to a semiconductor,then generally its resistivity

Which of the following statements is correct for an $n$-type semiconductor?

Let $n_e$ be the number density of electrons and $v_d$ be the drift velocity in a semiconductor. When the temperature is increased:

When a small amount of impurity atoms are added to a semiconductor,then generally its resistivity:

Which of the following energy band diagrams shows the $N-$ type semiconductor?

Indium impurity is added to a sample of $Si$ to prepare a $p$-type semiconductor. In this semiconductor,one atom of indium is added per $5 \times 10^7$ atoms of $Si$. The atomic density of the $Si$ sample is $5 \times 10^{28} \text{ atoms/m}^3$. How many acceptor atoms will be present in a $1 \text{ cm}^3$ cube of silicon?