Question

which atomic model states that it is impossible to know the exact location of electrons around the nucleus?
bohr model
dalton model
plum pudding model
electron - cloud model

Explanation:

The electron - cloud model is based on quantum mechanics. It states that due to the Heisenberg uncertainty principle, it's impossible to know both the exact position and momentum of an electron simultaneously, so we can't know the exact location of electrons around the nucleus. The Bohr model has electrons in fixed orbits, the Dalton model considered atoms as indivisible spheres, and the plum - pudding model had electrons embedded in a positive sphere.

Answer:

D. electron - cloud model