Most sodium atoms have an atomic mass of 23, but a few have atomic masses of 22 or 24. How do these isotopes differ from one another?
A. In the number of ions
B. In the number of neutrons
C. In the number of protons
D. In the number of electrons

emily ruth's annual premium is $1058.50

step-by-step explanation:

emily ruth is a female of 27 years age purchasing 20 year endowment insurance with face value $25000.

from the given table,

for females, the age of a male 3 years younger should be used.

so, we have to check for 24 year male for 20 year endowment.

it is 42.34 for every $1000 face value.

for a face value of $25000,

it is 25 * 42.34 = $1058.50

∴ emily ruth's annual premium is $1058.50

compass can be used day and night, cloudy or sunny