PLEAS HEL I BE FOR HEL

How many atoms are in a sample of copper, Cu, with a mass of 12.70 grams?

How many moles are in 7.2 x 10^23 carbon molecules? (*round to the nearest hundredth and include the unit "mol c" after your number) question 6 options:

Me i dont know what to do! the table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 10 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of the two atoms? both are unreactive. both are highly reactive. a is unreactive and d is reactive. a is reactive and d is unreactive.

Achemist who studies water samples did a demonstration of how to test for lead in water. she added a clear solution of potassium iodide to a clear solution of lead nitrate. then a yellow swirling solid formed in the liquid. what is most likely true about the yellow solid?