What do the bohr and quantum mechanical models have in common?

In both models, electrons move around a positively charged nucleus filling different energy levels called shells.  

Explanation:

Bohr's model places electrons in ascending energy levels orbiting in a circular motion around the nucleus. The quantum mechanical model also places electrons around a positively charged nucleus following ascending energy levels, but this time these don’t move in a circular manner but instead randomly inside clouds of probability.  

i'm pretty sure its b i might be wrong though!

answer: e.   sour taste

explanation: acids are those substances which dissociates in water to give ions. as they dissociate to give ions, they act as electrolytes and thus are electrically conductive. acids are sour in taste. example: hcl

bases are those substances which dissociates in water to give ions or accepts ions. as they dissociate to give ions, they act as electrolytes and thus are electrically conductive. bases are bitter in taste. bases are slippery in nature.