The unsaturated zone is the portion of the subsurface above the groundwater table. The soil and rock in this zone contains air as well as water in its pores. ... Unlike the aquifers of the saturated zone below, the unsaturated zone is not a source of readily available water for human consumption
Answer:
Explanation:
- For the balanced reaction:
<em>4Fe(s) + 3O₂(g) → 2Fe₂O₃(s).</em>
It is clear that 4 mol of Fe react with 3 mol of O₂ to produce 2 mol of Fe₂O₃.
- Firstly, we need to calculate the no. of moles of 35.8 grams of Fe metal:
no. of moles of Fe = mass/molar mass = (35.8 g)/(55.845 g/mol) = 0.64 mol.
- Now, we can find the no. of moles of O₂ is needed to react with the proposed amount of Fe:
<em><u>Using cross multiplication:</u></em>
4 mol of Fe is needed to react with → 3 mol of O₂, from stichiometry.
0.64 mol of Fe is needed to react with → ??? mol of O₂.
∴ The no. of moles of O₂ needed = (3 mol)(0.64 mol)/(4 mol) = 0.48 mol.
- Finally, we can get the volume of oxygen using the information:
<em>It is known that 1 mole of any gas occupies 22.4 L at standard P and T (STP).</em>
<em></em>
<em><u>Using cross multiplication:</u></em>
1 mol of O₂ occupies → 22.4 L, at STP conditions.
0.48 mol of O₂ occupies → ??? L.
∴ The no. of liters of O₂ = (0.48 mol)(22.4 L)/(1 mol) = 10.752 L.
The effective nuclear charge is an innate property of a specific element. It is the pull of force that an electron feels from the nucleus. It is related to the valence electron by the equation: Z* = Z-S, where Z* is the effective nuclear charge, Z is the atomic number and S is the shielding constant.
For the following elements in the choices, these are their values of Z*:
Aluminum - +12.591
Beryllium - +1.912
Hydrogen - +1
Carbon - +4
The effective nuclear charge of Boron is +3. Thus, the answers are Aluminum and Carbon.
Answer:
Renewable energy
Explanation:
on the other hand, typically emits less CO2 than fossil fuels. In fact, renewables like solar and wind power—apart from construction and maintenance—don't emit any CO2 at all. With renewable energy, you can breathe easier, stay cooler, and create a more comfortable world for generations to come.
