Answer:
Period 4
Explanation:
Given the electronic configuration of the element;
= Is² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p¹
The period of the element is determined by the highest coefficient in the electronic configuration.
For this given configuration (Is² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p¹), "4" is the highest coefficient and the element will certainly belong to period 4 in the periodic table.
To test if the prediction is correct:
Total number of electrons in the given element = 2+2+6+2+6+10+2+1 = 31
The element with atomic number of 31 = Gallium (Ga). (This element belong to period 4).
<span>The correct answer to this question might be a ratio of 3:1, simplified down from finding that there are 18 teaspoons in 6 tablespoons.</span>
Planck suggested that light/energy was absorbed/released in certain amounts, called quanta.
First, calculate the number of moles of sodium present with the given mass,
31.5 g of sodium x (1 mol sodium/ 23 g sodium) = 1.37 mol sodium
It is given in the equation that for every 2mols of sodium, one mol of H2 is produced.
mols of H2 = (1.37 mols sodium)(1 mol H2/ 2 mols sodium)
mols of H2 = 0.685 mols H2
Then, at STP, 1 mol of gas = 22.4 L.
volume of H2 = (0.685 mols H2)(22.4 L / 1 mol)
volume of H2 = 15.34 L
Answer: 15.34 L