What did ernest rutherford’s gold foil experiment demonstrate about atoms?

a. their positive charge is located in a small region that is called the nucleus.
b. their negative charge is located in small particles that are called electrons.
c. their nucleus makes up the majority of the volume of the atom.
d. their electrons are floating in a sea of positive charges.

option A.Their positive charge is located in a small region that is called the nucleus.

Explanation:

Ernest Rutherford’s gold foil experiment consisted in shooting positive particles called α particles, which are nucleii of helium atoms (2 protons and 2 neutrons), to a thin gold film.

Rutherford expected that most particles passed straight forward through the thin gold film and some to be slightly deflected.

But the results showed that, in spite of most particles passing straight forward as expected, some particles bounced off the film at great angles. This was totally unexpected.

Since, the α particles have positive charge, the explanation for this bouncing was given by the existence of a small nucleus that concentrated most part of the mass and was positively charged (such that this positive charged repeled the positive α particles).

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.