The astronaut then measures the abundance of magnesium on the new planet, obtaining the following results:
isotope abundance
(%) mass
(amu)
24mg 78.99 23.99
25mg
10.00 24.99
26mg 11.01 25.98
what is the atomic mass of magnesium for this planet?

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.

Carbon-14 undergoes radioactive decay in the reaction above. determine the type of radiation emitted in this reaction and describe what is happening to the nucleus during this reaction.

If e is the symbol for an element, which two of the following symbols represent isotopes of the same element? 1. e2. e3. ea.1 and 2c.1 and 4b.3 and 4d.2 and 3