Phosphorus (P) is diffused into a thick slice of silicon with previous phosphorus concentration 11016 atoms/cm3 in it at a temperature of 1100C. If the surface concentration of the phosphorus is 51018atoms/cm3 , and its concentration at 2m is 11017 atoms/cm3 , how long must be the diffusion time? D=310-13cm2 /s for P diffusing in Si at 1100C.

the leaf is an organ of a typical plant, and the main functions are to complete photosynthesis and allow the plant to exchange gas, just like how we have the respiratory system. leaves have the stomata, which collects maintains co2 and o2 levels. this is necessary for cell metabolism. the leaf also collects sunlight using chloroplasts. succinctly, leaves own a pivotal role in sustaining plant life.

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

i think that the answer is c