1- For an element, how does Avogadro’s number connect the atomic and macroscopic scales? It describes the number of grams in 1 mole of an element.

It describes the number of atoms in 1 gram of an element.

It describes the number of atoms in 1 mole of an element.

It describes the number of moles in 1 gram of an element.

2- The atomic mass of the element platinum (Pt) is 195.08 amu. How many atoms of platinum are in 195.08 grams?

6.022×1023 atoms

1.175×1026 atoms

1.951×1025 atoms

3.087×1021 atoms

3- The atomic mass of copper (Cu) is 63.546 amu, the atomic mass of sulfur (S) is 32.065, and the atomic mass of oxygen (O) is 15.999 amu. Which molar mass is correct for copper sulfate (CuSO4)?

159.607 g/mol

225.802 g/mol

111.610 g/mol

446.440 g/mol

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.