How many atoms of chromium are in 8.3 moles of aluminum dichromate

3.00x10²⁵ atoms of chromiun

Explanation:

The formula of aluminum dichromate is Al₂(Cr₂O₇)₃.

In the formula it is seen that for each molecule of the compound, we have 6 chromium atoms, so in one mole of it, there are 6 moles of chromium. With this information you can calculate the amount of chromium atoms using Avogadro's number.

Since we know that in one mole there are 6.02x10²³ molecules of aluminum dichromate, and in each molecule there are 6 chromium atoms, so the following relationship can be established:

1 mole Al₂(Cr₂O₇)₃ 6 x (6.02x10²³) Chrome atoms

8.3 moles X = 3.00x10²⁵ atoms

Calculation:

8.3 moles x [6 x (6.02x10²³)] / 1 mol = 2.9979x10²⁵ atoms ≅ 3.00x10²⁵atoms

The answer, then, is that there are 3.00x10²⁵ chromium atoms in 8.3 moles of aluminum dichromate

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

- decrease the number of plants and animals living in the water.