Compare similarities and differences between the plum pudding model, nuclear model and bohr model (6 marks)

The three models describes the structure of an atom based on different views.

Explanation:

Plum pudding model described the atom of consisting of negatively charged electrons embedded in positively charged substrates; this was later proven to be false. The Bohr's model described the electrons in an atom to orbit round the nucleus at different energy, the closer it's to the nucleus, the lesser the energy it needs. The Rutherford model claims the the nucleus of the atom contains protons and neutrons which forms the mass of the atom, the electrons surrounds the nucleus and it forms the volume of the atom.

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.

answer: -

reaction:

na + cl ⇌ nacl

balanced chemical equation:

na + 2cl ⇌ nacl2

sodium + clorine goes to form sodium chloride (table salt).

the product is nacl2.

and the reactants are na and cl.

(note: if you don’t know what ⇌ means, read below: -

⇌(double head arrow) means reversible reaction).