Answer:

Explanation:
First you should calculate the volume of a big sphere,so:



Then you calculate the volume of a small spehre, so:



Finally you subtract the two quantities:


As one element .because po4 is phosphate for e.g.: NaPO4
Metals of Group 1 donate 1 electron from its ns orbital to form ionic bond, where n is the no. of its outermost shell.
Metals of Group 2<span> donate 2 electrons from its ns orbital to form ionic bond, where n is the no. </span>of its <span>outermost shell. </span>
Answer: E = 2.455 x 10^5 N/C
Explanation:
q1 = 1.2x10^-7C
q2 = 6.2x10^-8C
Electric field, E = kQ/r²
where k = 9.0x10^9
since the location is (27 - 5)cm from q1
hence electric field, E1 = k*q1/r²
E1= (9x10^9 x 1.2x10^-7)/(0.22)² = 22314.05 N/C
for q2:
E1 = k*q2/r²
E2 at 5cm
E2 = (9x10^9 x 6.2x10^-8)/(0.05)² = 223200 N/C
Hence, the total electric field at 5cm position is
E = E1 + E2
E = 22314.05 + 223200 = 245514.05 N/C
E = 2.455 x 10^5 N/C
Coal can replace petroleum base fuel when you are just heating something that dont need big amount of heat. examples of it is when producing steam, coal is just used to heat water and produce steam because coal is much cheaper and the coal can already do the job in heating the water