A radioactive isotope has a half-life of 5700. years. Given a 100.0 gram sample of the isotope initially, after a number of years have passed, we find that only 6.250 grams of the original isotope remain.
How many years old is the sample?
a 2.280 x 104 yr
b 1.140 x 104 yr
c 1.710 x 104 yr
d 2.850 x 104 yr

According to the valence shell electron pair repulsion (vsepr) theory, a molecule that has four electron groups around the central atom will exhibit what electron geometry? view available hint(s) according to the valence shell electron pair repulsion (vsepr) theory, a molecule that has four electron groups around the central atom will exhibit what electron geometry? trigonal bipyramidal tetrahedral square planar determination of electron geometry requires information on whether the electron groups are lone pairs or bonding groups.

No copying 15 pts how does a free-body diagram tell you about the net force on an object?

Afusion reaction takes place between carbon and another element. neutrons are released, and a different element is formed. the different element is a) lighter than helium.b)heavier than helium.c)the same weight as helium.d)dependent on the element that reacted with carbon.