Answer:
The number of outer shell electrons determines the group number of the element. The number of occupied principle quantum shells (energy levels) determines the period of the element. The proton number determines the element itself and its position.
Explanation:
Z sorry if it’s wrong good luck
Answer:

Explanation:
Hello!
In this case, since we are given the formula units (molecules) of copper sulfate, it is possible to compute the moles of this compound via the Avogadro's number:

Now, given the molar mass of copper sulfate which is 159.60 g/mol, the required mass in grams turns out:

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Answer:
124 g (3 sig figs)
or
124.011 g (6 sig figs
Explanation:
Step 1: Calculate g/mol for AgNO₃
Ag - 107.868 g/mol
N - 14.01 g/mol
O - 16.00 g/mol
107.868 + 14.01 + 16.00(3) = 169.878 g/mol
Step 2: Multiply 0.73 moles by molar mass
0.73 mol (169.979 g/mol)
124 grams of AgNO₃
Answer:
Chilling the hydrogen peroxide solution
Explanation:
The MnO₂ is acting as a catalyst.
Chilling the hydrogen peroxide solution reduces the average kinetic energy of the H₂O₂ molecules.
Fewer of them will have enough kinetic energy to overcome the activation energy of the reaction. The rate will decrease.
A is wrong. Using a larger amount of solution does not increase the number of H₂O₂ molecules that can reach the surface of the catalyst per second. There is no effect on the rate.
B is wrong. Increasing the mass of the cube increases its surface area. More molecules of H₂O₂ can reach the surface of the catalyst per second. The rate increases.
D is wrong. Smashing the cube into pieces vastly increases the surface area, so the rate increases