will give branliest!
10 points!
- how many grams of Al2O3 contain 3.45x10^20 atoms of Al2O3?

0.058 g of Al₂O₃

Explanation:

Al₂O₃ → Aluminum oxide

The molar mass is 101.96 g/mol. Therefore 1 mol (NA molecules) are contained in 101.96 grams

NA = Avogadro's number → 6.02×10²³

We make a rule of three to determine the grams we were asked for.

6.02×10²³ molecules are contained in 101.96 g

3.45×10²⁰ molecules will be contained in (3.45×10²⁰ . 101.96 g ) / NA = 0.058 g

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.

alchemy hadn't scientific methods of study, appeal to mysticism and fantasy, the knowledge of chemistry and physics were modest at that time.

alchemy was - but as new rules were discovered it either changed into chemistry or it became "unscientific".