What is the empirical formula for a compound which contains 80.2% zinc and the rest is oxygen

The empirical formula for a compound : ZnO

The empirical formula is the smallest comparison of atoms of compound =mole ratio of the components

The principle of determining empirical formula

Determine the mass ratio of the constituent elements of the compound.  

Determine the mole ratio by by dividing the percentage by the atomic mass

Percentage Oxygen :

100\%-80.2%=19.8\%

mol ratio for Zn : O =

the answer is a

photosynthesis

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.