Henlo!
Bohr's model was unable to calculate or it required precise information about position of an electron and its velocity. It is very difficult to calculate velocity and position of an electron at the same time because electron i too small to see and may only be observed if peturbed, for example we could hit the electron with another particle such as photon or an electron, or we could apply electric or magnetic field to the electron. This will inevitably change the position of the elctron or its velocity and direction. Heisenberg aid that more precisely we can define the position of an electron, the less certainity we are able to define its velocity and vice versa.
In short, first option is correct one
Answer:
Universe, galaxy, solar system, star, planet, moon and asteroid.
Explanation:
You're welcome!
Sure. Whith what do you need help?
The appropriate answer is a. it involves a change in the molecular structure of the substance. A change in phase or state is referred to as a physical change. For example...liquid water freezing is a physical change because the state changes but solid water is still H20. Separating water into its constituent atoms, hydrogen and oxygen is a chemical change because the molecular structure of water is now non existent.
Calculating speed or atoms and molecules or planets!
Hope i helped plz mark as brainlist!
