Answer:
Explanation:
The surface soil, or topsoil layer (O and A horizon in Figure 1–2), usually contains less clay, but more organic matter and air, than the lower soil layers. Topsoil is usually more fertile than the other layers and has the greatest concentration of plant roots.
Answer: The volume of 0.684 mol of carbon dioxide at s.t.p. is 15.3 L
Explanation:
According to ideal gas equation:

P = pressure of gas = 1 atm (at STP)
V = Volume of gas = ?
n = number of moles = 0.684
R = gas constant = 
T =temperature =
(at STP)



Thus the volume of 0.684 mol of carbon dioxide at s.t.p. is 15.3 L
Answer:
5.37 L
Explanation:
To solve this problem we need to use the PV=nRT equation.
First we <u>calculate the amount of CO₂</u>, using the initial given conditions for P, V and T:
- P = 785 mmHg ⇒ 785/760 = 1.03 atm
- T = 18 °C ⇒ 18 + 273.16 = 291.16 K
1.03 atm * 4.80 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 291.16 K
We <u>solve for n</u>:
Then we use that value of n for another PV=nRT equation, where T=37 °C (310.16K) and P = 745 mmHg (0.98 atm).
- 0.98 atm * V = 0.207 mol * 0.082 atm·L·mol⁻¹·K⁻¹ * 310.16 K
And we <u>solve for V</u>:
Answer:
If it loses 2 electrons, the net charge on the atom will be 2+
If the atom instead gains 4 electrons, the net charge will be 4-
Explanation:
It is based on adding and subtracting charges. Protons are +1 and electrons are -1
If the atom has 9 protons and 9 electrons, the net charge is +9 + (-9) = 0. The +9 is the 9 protons and the -9 is from the 9 electrons.
If two electrons are taken away, there would be 9-2 or 7 electrons with 9 protons. The net charge would then be +9 + (-7) = +2. +9 comes from the 9 electrons and -7 is from the 7 electrons.
So, if two electrons are taken away, the net charge is +2.
Similarly, if the atom gains 4 electrons, there will be 9+4 or 12 electrons and 9 protons. The net charge would then be +9 + (-12) = -4. +9 comes from the 9 protons and -12 comes from the 12 electrons.
So, if 4 electrons are added, the net charge is -4.
Answer:
Using cobalt glass could be helpful to identify elements that weakly emit blue and/or violet.
Explanation: