Aresting adult requires about 240 ml of pure oxygen per minute and breathes about 12 times every minute. if inhaled air contains 20 percent oxygen by volume and exhaled air 16 percent, what is the volume of air per breath? (assume that the volume of inhaled air is equal to that of exhaled air.)

55.55 mL

Explanation:

Breathing is the process of inhaling air into and exhaling out of the lungs.

Total amount of oxygen required per minute = 240 mL

No. of breaths per minute = 12

Amount of oxygen required per minute

One breath = 1 inhalation + 1 exhalation

Lets assume, volume of air per breath = mL

Volume of oxygen in inhaled air = 20%

Volume of oxygen in inhaled air = 16%

Total volume of oxygen during one breath = (20%) + (16%)

This implies,

Thus, volume of air per breath = 55.55 mL

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.