PLEASE HELP FAST ! Calculate the mass in grams of each of the following . 2.0•10^23 gold atoms 1.5•10^23 lead atoms 7.9•10^21 uranium atoms

2.0 x 10²³ atoms Au = 65.4g

1.5 x 10²³ atoms Pb = 51.6g

7.9 x 10²¹ atoms U = 3.1g

Explanation:

We want to convert each to grams.

We can use dimensional analysis to do so.

Kindly view the attached image for work.

1.) 2.0 x 10²³ atoms Au

Needed conversions:

Math: (2.0x10²³atoms)/(6.022x10²³atoms) x 196.966g = 65.4g

2.) 1.5 x 10²³ atoms lead

Needed conversions:

Math: (1.5x10²³atoms)/(6.022x10²³atoms) x 207.2g = 51.6g

3.) 7.9 x 10²¹ atoms U

Needed conversions:

Math: (7.9x10²¹atoms)/(6.022x10²³atoms) x 238.029g = 3.1g

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.