The work function of an element is the energy required to remove an electron from the surface of the solid. the work function for rhodium is 480.5 kj/mol (that is, it takes 480.5 kj of energy to remove 1 mole of electrons from 1 mole of rh atoms on the surface of rh metal). what is the maximum wavelength of light that can remove an electron from an atom in rhodium metal?

Explanation:

Given that:

The work function of the rhodium = 480.5 kJ/mol

It means that

1 mole of electrons can be removed by applying of 480.5 kJ of energy.

Also,

1 mole =

So,

electrons can be removed by applying of 480.5 kJ of energy.

1 electron can be removed by applying of of energy.

Energy required =

Also,

1 kJ = 1000 J

So,

Energy required =

Also,

Where,  

h is Plank's constant having value

c is the speed of light having value

So,

Also,

1 m = 10⁻⁹ nm

So,

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

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.