Answer:
40%
Explanation:
We'll begin by obtaining the molar mass of MgO. This is illustrated below:
Molar Mass of MgO = 24 + 16 = 40g/mol
Observing the formula MgO, we have 1 atom of O in it.
The percentage composition by mass of oxygen in MgO is given by:
Mass of O/Molar Mass of MgO x 100
= 16/40 x 100 = 40%
1. an alpha particle
gamma rays are formally massless, positrons and electrons (beta particles) have negligible mass, but alpha particles have about 4 amu of mass
Scientific notation is defined as writing a number between 0 to 10 multiplied by a power of 10
3.5 x 10² x 8.0 x 10⁻²
when we solve the equation
answer - 28
to write in scientific notation the decimal point should come after the first digit from the right. to bring the decimal point from after digit 8 to after digit 2, we have to move one decimal place to the left. then we get 2.8, to get the value as 28 we have to multiply 2.8 by 10
therefore answer is
2.8 x 10¹
