Sec 2 | Chemistry | Quiz 1 | Chapter 1| Lesson 1&2

Each of the following is among Dalton's Theory postulates, except that ----------

• atoms of the elements contain protons, neutrons and electrons.

• The masses of the atoms of the same element are similar.

• The atom is invisible.

• Each element is formed of tiny particles called atoms.

Delton and Thomson agreed on that carbon atom ------

• Has no spaces within it.

• Is electrically neutral.

• Contains negative electrons.

• Is a homogeneous sphere.

The gold foil experiment which is carried out in Rutherford's lab ------

• Confirmed Thomson's atomic Theory.

• Is the base for Dalton's Theory.

• Led to discovering the nucleus of the atom.

• Used in it a source of beta particles.

When alpha Particles and cathode rays are exposed to an electric field or a magnetic field, they ---------

• Move with the same speed.

• Pass in opposite directions from each other.

• Pass together in the same direction.

• Are not affected by either of them.

The strong evidence that proved that cathode rays exist in all matters -------

• they have thermal effect.

• they flow in straight lines.

• they consist of fine particles.

• they have the same properties and behavior whatever the gas or the cathode material used.

When an electron transfers from an energy – level near to the nucleus to a further one , it will -------

• lose a quantum.

• gain a quantum.

• radiate energy.

• don't lose a part of its energy.

When a photon of light with wavelength 486 nm transfers from an electron in the principal level (n=4) in hydrogen atom, this electron transfers to the principal level --------

• n=1

• n=2

• n=3

• n=5

If the difference in energy between energy levels K and L =  $\Delta\ E_1$ , then the difference in energy between energy levels O and P is ------

• higher than  

   $\Delta\ E_1$ 

• equal   

   $\Delta\ E_1$  

• lower than  

   $\Delta\ E_1$

• approximately 

   $\Delta\ E_1$ 

According to Bohr's atomic model, the electron ------ how to transfer from first level K to the fourth level N

• Acquires a quantum

• loses a quantum

• Acquires 4 quanta

• loses 4 quanta

" The actual position of the last electron in iron atom and its speed in a certain moment cannot be precisely determined".

The previous statement is an application of -------------------

• Hund's rule.

• Bohr's model.

• The dual nature of electron.

• Uncertainty principle.