What is an atomic nucleus? the outer part of an atom in which electrons move
the outer part of an atom in which neutrons move
the central part of an atom, composed of protons and neutrons
the central part of an atom, composed of protons and electrons

Idon't really understand this can you me and show your work.☺☺[ chemistry b] subject [ electron transfer in lonic bonds]grade( 12)

Lab reagent, hypothesis test. a reference solution used as a lab reagent is purported to have a concentration of 5 mg/dl. six samples are taken from this solution and the following concentrations are recorded: (5.32, 4.88, 5.10, 4.73, 5.15, 4.75) mg/dl. these six measurements are assumed to be an srs of all possible measurements from solution. they are also assumed to have a standard deviation of 0.2, a normal distributin, and a mean concentration equal to the true concentration of the solution. carry out a significance test to determine whether these six measurements provide reliable evidence that the true concentration of the solution is actually not 5 mg/dl.

How does the viscosity of magma change as magma cools?